What is Has Her Back?
1.
"Has her back" refers to the situation where a gay person, male or female, has a friend who fills-in or runs cover as an apparently heterosexual companion or sidekick.
"She is cute as a button, queer as Amelia Earhaedt, and that asshacker Bob has her back."
" That new dude is a faggot, the queer upstairs thinks he has her back. Not!"
See