At what age do babies begin to not like certain people?

My son did this with his paternal grandmother too. I will tell you like my sister told me, "babies can sense evil." Now maybe your mother in law is fine, but mine is horrible and my baby seemed to know it.

Usually babies start to make strange around 6 months old. Your daughter seems a little early to be doing this, but I suppose anything is possible. Try spending more time with the grandmother, so the baby gets used to her. Either that, or wait it out - it should pass eventually.

My daughter used to do this to my sister's husband. Was the funniest thing ever! She would cry and shake and strain to get away. She started to grow out of it at around 2.5 and now she's fine and has no problems with her Uncle.

I know I'm not very helpful. I think you should just give your daughter space and when she's ready, she'll approach her gandma. Grandma should not force herself onto your child.

I think 3 months is old enough to dislike someone-I'm pretty sure my daughter hated my in-laws by 3 months :)

My son went through a phase about being very picky about people from 3-9 months.

After 9 months, he became very social and liked everyone.

He is now 13 months and extremely social. He loves everyone and is very interested in new people.