I think seeing the pediatrician is a good idea. From what you've written, it sounds like your dd is really doing very well, and while she may be behind in speech my guess is it's simply because she's been focusing on learning other things. Most of the young children I've known (gifted or not) tend to develop in spurts where they'll make leaps and bounds of progress in one area but maybe seem not quite on track in another, then all of a sudden the area that they didn't seem to be making forward motion on leaps ahead too... more so than steady linear across-the-board progress. That said, my ds12 didn't talk until he was 3, and made very few sounds ever, didn't babble. We didn't think anything was going on at the time simply because he was ahead of the game in other areas, and we didn't have him evaluated for speech when he was young. Fast forward to mid-elementary school and although he was a very verbal kid, he also had an expressive language disorder and he's been in speech therapy for several years now. I can't help but wonder if he would have been farther ahead earlier on if we'd taken him for EI when he was little.
It never hurts anything to take your child in for an evaluation - every eval any of my kids have had has been mostly fun for my kids
If you find out nothing's up, that's good information! And if you discover that there is a challenge, the earlier you can start working on it the better you'll feel and most likely the better progress your dd can make and it will make things easier once she's older and in school.
Re the sensory things - having a professional help you sort those out will also be worthwhile - they can be due to soooo so many things, including personality and possibly just a phase. My older dd is a highly sensory kid - when she was young she screamed (we're talking Horror Flick level screaming :D) whenever she went anywhere new. It started at 2 and got so bad by the time she was 4 we couldn't take her *anywhere* she hadn't already been before and was comfortable. We took her to see a psychiatrist at 4 who recommended sensory OT and it helped quite a bit, but ironically it didn't help the real challenge, just gave her a way to cope with her sensory overload. We found out later, when she was in 2nd grade, that she was seeing double vision and that was what was really going on when she was so young and we took her to new places - she was freaked out because she couldn't see. She also had heightened auditory awareness because she relied on her hearing due to the sight challenges, which had an additional impact when she was somewhere new where there was noise or a lot of people etc - it was much noticeably loud to her than to us. So what I'm trying to say is - it may just be sensory with your dd, or it could be that what looks like a sensory challenge is a reaction due to some different type of challenge. Our dd is still relatively sensory even though she's much older now and her vision is corrected and she's not afraid of new places - she still has very sensitive hearing, responds to touch/odors etc, and she is still a "screamer" in perhaps a more grown-up type of manner - she can get quite dramatic over very little things, such as how to use a matrix of coins to explain multiplication (last night's math homework).
Sorry, getting off track here - but fwiw I think you're doing the right things - trust your instincts and you (and your dd) will be fine
Best wishes,
polarbear
ps - I agree with the others who said not to drop the signing - that's her way of communicating and she's good at it and getting her message across. You can also tell that she's not behind in receptive language thanks to her signing and actions.
