4 yr old daughter can't pronounce the letter L. If it is at the beginning of a word she pronounces it as a Y, so look would be yook and if it's in the middle of a word then she misses it out completely, so please would sound like peas. Is this normal ? A health visitor did pick up on it when she was 2 but later dissmissed it. I didn't used to notice it that much until I noticed that some people couldn't understand her. None of her teachers at nursery have mentioned it though so i'm not sure if i should be concerned or not.