Shy

We took daughter to the kindergarden open house today she won't talk to the teacher and just hid behind us. She is like this she won't say Hi if we ran into people or meet friends. she has been going to daycare since one, I don't understand why she acts like this, teacher from daycare told me she is fine at daycare.We took her to the swimming lesson she won't even go into the water with the coach. Does anyone have same experience?