Aisha doesn't know why she stays.
She hates Clay, still, for what he's done, but sometimes she's just so tired of hating - her father had a lot of enemies and just because Clay's the one who killed him doesn't mean that no one else was going to try.
So Max is first on her list, she's going to kill him, no question. And Clay's still there, although somehow his name keeps slipping further down to the bottom of the list. His unit is on there too, because Aisha doesn't leave loose ends, and if she leaves them alive there's gonna be one hell of a loose end; just enough to hang her.
Sometimes she forgets to hate them though - when she realises that Jensen's natter soothes her to sleep better than thoughts of revenge, when Cougar proves he knows more ways to kill a man than she does and is willing to share his knowledge, when Pooch chooses the most inappropriate vehicle possible for them to escape in, picture of his son replacing the nodding dog on the dashboard.
And when se looks up from cleaning the guns, and sees Clay watching her from across the campsite, and there's heat in his eyes, yes, but also fondness, and she finds herself smiling back without thinking of his death. And slowly she realises that these men, these 'bad men' who care so much and who watch her back as well as their own, are filling in the hole her fathers death left in her life.
She's still going to kill them though, because she made a deal with herself, and Aisha always keeps to her end of a deal.
But she might wait a little longer, until they trust her more, let their guard down, show her their soft targets. And she has to teach Jensen to flirt first, because no one that hot should be this hopeless with women. But she's definitely going to kill them. Because she doesn't like them. She certainly doesn't love any of them. No, Aisha has no idea why she stays.