You do know that there was this well known physicist who didn't speak until he was 3 and was still not fluent as other children until he was 9.

Is there any part time preschool or day care you can take your child to for socializing? or any other kids the same age in your area? Perhaps if she's among kids her age, it may encourage her to talk.

Our 4 year old is still finding her voice too.  She seems to be rather lazy with her speech and will grunt or squeal instead of asking for something.  We keep prompting her to speak and ask or she won't get what she wants.

I've been told not to worry about it until she goes to school as she has developed a lot faster in other areas, like climbing and finer motor skills.