The episode's title "Gallavich", a portmanteau of Gallagher and Milkovich, has been used for years in the Shameless fandom to refer to Ian and Mickey's relationship, in a similar way that "Brangelina" was used to refer to former real-life couple Brad Pitt and Angelina Jolie, or "Sterek" was used by Teen Wolf (2011) fans who wanted to see Stiles Stillinski end up with Derek Hale.
Fiona, the Gallagher's oldest sibling, does not appear nor is she mentioned.
There's been a lot made of Julia being younger than Debbie and being underage, however Alison Jaye is actually nearly 3 years older than Emma Kenney, being nearly 24 when this originally aired.