Baby not liking people

My little girl used to not care who held her at all and now she's 3 months old and for some reason if my nana or step mom try to hold her she just starts screaming really bad. We thought she might have had an earache or mouth ache from teething or something but she literally is perfectly fine any other time so I don't know what her deal is. She let's my younger siblings hold her some times but the second my nana or step mom even touch her she freaks out. Does anyone have this problem or know what it could be? It's kind of starting to worry me. Like I don't know why she hates being messed with by them they don't make annoying sounds or anything they do exactly what I do so I don't know what it is.