L.O.
Every one will tell you how to raise your child.. there is no shortage of child rearing opinions.. You just have to let it roll off and pay no attention.
Every child is different..
My duaghter was afraid of everyone- from 6 weeks old she knew I was the momma and she only wanted the momma. She didnt let anyone hold her. There was quite a while when even daddy couldnt hold her.
I started taking her to activities at 21 months.. story times nd playgroups.. etc... she was well behaved but did not interact with the teachers.. She played and did not cling but interact with other adults.
It took until about 30 months until she started interacting with adults.. she is still reserved around most men. she will talk to most women.
My son is a differnt person - he was born loving everyone. He attended playgroups and lessons from 4 months old.. (with his sister) He has always gone up to strangers to be picked up and is very friendly..
I am sure this is your daughters personality.. It will probably improve overtime but she may always be a bit reserved.. which is perfectly normal..