Title basically, she did her postdoc at Princeton and I was wondering if that counts as having been an alumna or former employee of Princeton. If it is, would it help at all, and should I apply SCEA?
no. you should apply SCEA if you are a candidate that matches or exceeds the successful Princeton applicants and you want to go there–but your mother being a graduate student will not help. (unless maybe she is someone famous or otherwise of note)