If you say Walt killed Jane, you’re just looking for a reason to hate Walt. Jane killed herself, and if anything, Jesse helped.
actually if you re-watch that scene, jane starts out perfectly fine laying on her side. once walt starts shaking jesse, he knocks jane out of the way ever so slightly and she rolls on to her back before choking on her own vomit. if walt hadn’t come it at all or hadn’t touched jesse, jane wouldn’t have died.