Jill getting the flat/apartment makes more sense to me; she'll have the freedom to come and go, the MC can stay there at times or she can visit him at the frat or do like Elena and Heather are doing as was mentioned. Tybalt can't push her out, and I doubt she can push him out. So the only option is for her to voluntarily leave and go somewhere else, someplace where she doesn't have to look at him anymore.
Because she can't do what she did, then live back in the mansion and cross paths with him every time. I mean, where did she go after that night her and the MC walked away from him? To Bella's? That's what I'm assuming. For her to rip him a new hole then walk back in to the mansion seems silly to me.
For now, at least she has options; Bella, her other friends, or a place of her own.