My 14 month old is average to advanced verbally when she's around us. She started talking early and we've stopped counting words, but she is will ask for things with words before using signs, knows all her animal sounds and basic body parts, imitates what we say all the time (and will repeat it later), and babbles to herself constantly while playing alone or talking to family.

HOWEVER, she apparently will not talk AT ALL with her teachers at school! Her teachers say she obviously understands everything they say, but she won't talk when they ask her questions or otherwise (except sometimes talking about the "babies" in the infant room, but "baby" is her favorite word). She'll start talking away and usually respond to questions as soon as I'm there to pick her up.

Should I be worried? She seems perfectly happy at school otherwise, and she is the youngest one in her class...

Any insights?