Spoiler Eh... Girl's gotta eat right? Plus you could easily write reasons she could be forced to still work for a clandestine intel agency. After all even in the post cred scene Lang and the Pyms were attempting to gather more "healing energy particles" (Ugh... I just find that deus ex macnina so lame) to help her specifically which indicated to me that whatever Janet did with her pulled out the ass super healing hands wasn't a permanent solution, ANNNNNND... They didn't end up getting that for her so given however A4 ends she could still be in need of her chamber or some kind of therapy. Boom, there's something that could be held over her to press her into service.