During Are You There Shim? It's me, Ian, Tami attends the wedding of her sister Cammi and Brad, she talks with Brad's best man Lip for a good while. She invites him to a hook-up with her but she ends up puking on him. At Brad's suggestion, Lip asks Tami out but she turns him down while deriding his skills in bed and sends the insulted latter off while mockingly calling him "Jabby".
In Down Like the Titanic, Tami shows up drunk at the christening of her nephew Miles, while Lip and Jason (a boy that he is sponsoring) informs Jason of their encounter. Cammi is annoyed at Tami showing up late while she states it was because of parking, before she takes note of Lip and is amused to see him again. She harasses Lip later about her latest sexual exploits, even jokingly offering another chance but he rebuffs her and she asks about Xan. Lip then reveals Xan went back to her mother while he is sponsoring Jason who says the same went for his child. Wanting out of the depressing scene, she spends time with her nieces and nephews by giving cigarettes to them. After Lip sees Jason off, Tami meets him again and they share a smoke before she decides to take him up on his previous date offer since she was bored. The two go for tacos and talk about having harsh lives with their families, until she offers him the chance to redeem himself in sex and he takes her up on it. They have sex in her car and Tami rates him as better than before but critiques him as not enough (being 6 out of 10), this causes him to tell her they will try again until she admits that she is wrong about him. She is amused by this attitude and they continue the encounter. Very soon, Lip redeems himself and he offers Tami another chance at a date and she accepts it. It seems Tami took a liking to him, as she brings him in for a passionate kiss and they part with another joke.
As seen in The Apple Doesn't Fall Far From The Alibi, Tami and Lip are still seeing each other but are not serious yet. Tami tries to persuade him to get an apartment, while he asks her to move in with him. She sees the life at the Gallagher Household, where the house is dilapidated and how he is with his siblings. Tami decides to help them move from their way of life. At the end, she spends the night with Lip and watches as his drunk sister Fiona is brought home and asks if she does that a lot.
In BOOOOOOOOOOOONE!, she and her family pay tribute to her mother by walking in support of fighting cancer. Tami invites Lip and he meets her other sister Cori who makes advances on him, despite arguing with Tami on this. Tami is also reunited with her ex-fiancé Boon who still has feelings for her. Tami is also not impressed by Cori flirting with Boon to as her sister tells her that she can't have everyone. Later, Tami visits Lip and he questions her on her former fiancé and they argue for a while until she leaves. At her home, Tami is visited by Lip and informed he slept with her sister but she shows no reaction and he questions this. Tami gives her reasons, stating they were just sleeping around, like she's doing with her ex-fiancé. As Lip sits down, Tami decides to open up and reveal that it does bother her. They decide to put in the effort of starting a relationship while promising to not sleep with Cori or Boone again.
As of Los Diablos,Tami and Lip are still seeing each other and they seem to really putting in the effort. While returning home, Lip and Tami find Xan who had returned after her mother ditched her once again and she had nowhere to go. Tami shows concern for the girl when learning of her ordeal with truckers when her mother left.
During The Hobo Games, Tami develops a flaky behavior and doesn't answer his calls. Later on, she is with her friends before Lip catches up to Tami and ask her what's up with her recent behavior, as she reveals herself to be pregnant. Lip is shocked and questions if it is his as she confirms she's carrying Lip’s child, since she forced Brad into wearing confoms.
In You'll Know Bottom When You Hit It, Tami's sisters confront Lip on his acts with her but he explains that he didn't do anything and reveals her odd behavior towards him. Lip later confronts Tami on this and they talk with her revealing she is unsure of whether to have her child and he tells her they could discuss it.
As of Lost, Lip meets with her and tells her that her father showed up to ask about his plans for the baby, and tried to "decide" that Tammi is having the baby and it's not up for discussion. Tami is annoyed her father did so and once more rants about others controlling her life. Tami then reveals her sisters are cancer free but she is unsure of hers, which is why she isn't sure about having the baby for health reasons. Lip assures her and she goes for the results and is still nervous. After going to the doctor, she is worried about the results and offers sex to calm her nerves and he complies.
During Found, Tami continues to see Lip and reach an understanding. They go to his house where she watches as his father is bathed by a male nurse and comments on it. After Fiona told Lip that she is leaving and he asks his sister to stay for a party to say goodbye, Tami runs up to tell Lip about the nurse situation. She realizes that she ruined their moment but Fiona tells her to take care of her brother and smiles. Tami helps Lip gather party items though they see Fiona already left but they party anyway.
In We Few, We Lucky Few, We Band of Gallaghers!, Tami is still seeing Lip and is heavily pregnant. She is now more loving to Lip and they appear happy but Brad warns Lip it won’t last long. While at work, her water breaks and she goes to the hospital where she goes into labor. She is forced to have a C-section but gives birth to a son. However, the stress puts her in rare unresponsive condition as she is forced to stay overtime.
During Which America?, Tami is recovering from the birth and is visited by Lip. She is happy to see him but tells him that she is not fine. However, Lip tells her that he has a surprise and introduces her to their son Freddie Gallagher. Although put off by the name, she is nonetheless pleased to see her child and calls him beautiful. She is unable to hold him because of her pain and comments she wishes he didn’t see her like this.
During A Little Gallagher Goes A Long Way, Tami has been discharged from the hospital and goes to the Gallagher Household. Tami finds the family having a party and is surprised by the situation. Lip surprised to see her again and they hug before she mistakes his new friends baby as Fred. However Debbie introduces her to the real Fred and she finally hold him, pleased by this.
- She mentions several sexual encounters even some at camp and school.
- She initially gave Lip a 6 out of 10 but later 9.5 in his skill in their second sexual encounter.
- According to her, the women in her family die of ovarian cancer at age 50 so she believes twenty five years left to live.
- She mentions that instead of "experimenting" with a lesbian she instead "experimented" with one of her room mates, Brian, who she currently finds very annoying as he doesn't pay for rent and Brian tries to justify this by stating "I buy the coffee" which he offered Lip once for $5 a cup, and with the total of his 3 room mates living in the apartment means he only pitches in for beverages that in total cost $15, or $20 if he gives his coffee to someone else. He is considered to be so annoying to point where both Lip and Tammi show that they're both disgusted by the fact that Tammi dated him (showing that the relationship did not end well, and Tammi clearly regretted it).
- She afraid of heights.
- Tami initially wanted Fred’s name to be Gabriel but Lip revealed she agreed while she was high on pain medication.
- Her family are old school Catholics.
- Lip considers her to be the least crazy out of all his sexual partners.