Use stream of consciousness to answer the following. In this season, Frank starts a successful homeless shelter, but later gets kicked out despite owning the property. He later finds out that Monica has terminal brain damage. The two try to make the best of Monica's last days. Fiona struggles with owning two separate properties, and is happy being single. She begins to use Tinder to find one night stands to "save energy" on other things. Carl is uncircumcised and tries to keep his girlfriend whose father greatly disapproves of him. He later forms a bond with her father and leaves for military school. Lip dates Sierra, who works at Patsy's Pies, and struggles to stay sober. Ian refuses to take his medication and meets a new boyfriend named Trevor. He later finds out Mickey is out of prison. Debbie struggles to raise and keep Franny as she gets kidnapped by Derek's family. Kev and Veronica continue their "thrupple" with Svetlana until they find out Svetlana lied and betrayed them.

Answer this question based on the passage: who is lips girlfriend in shameless season 7?
This is the relevant information: Lip dates Sierra, who works at Patsy's Pies, and struggles to stay sober. Final answer: Sierra.