C.K.
Don't worry about how your daughter will do on the eval...any speech pathologist that works with young children will not expect your dd to be instantly comfortable with a stranger! Most of the eval will be talking to you, getting some development history, learning what your dd does say and when she says it. Some of the eval will be all about play, the speech path will likely bring some new toys that may help your dd "open up." No performance anxiety for a toddler!! She is who she is, and any good speech path will understand and respect that. If you have further questions, I am a speech path and would be happy to talk with you.