As I mentioned before, Ada's been a bit slow to talk so far and at her 1.5 year checkup, the doctor encouraged me to pay attention to Ada's speech and work with her to improve her language skills.
To do so, I called a friend who is a speech pathologist and she gave me a bunch of pointers. (Play games where you name stuff, give Ada options - Apple or Orange?, use picture books and repeat names of everyday items, point to your mouth to show Ada how a sound is made and repeat it for several items - bunny, ball, broom, book, bag, bubbles, stop using sign language and doing everything for her, etc.) Rick, our nanny and I have been working with Ada a lot lately and trying out best to get her speaking. She's now going on 20 months and I'm starting to see improvements. Now she's saying Dadda and Momma when we are around respectively instead of just babbling. She says Ba for Ball -- doesn't quite have the L sound on the end. And we keep hearing words come out even if she doesn't ever repeat them again (making me wonder if I'm crazy and making it all up.) I think Ba Ba is baby. She has other sounds she makes too so that's good (according to my friend the speech pathologist). Her cognition is great (as they say) and she's understanding more and more as we work with her. I used to think that we could just sit in the same room with her and she'd absorb all the fun stuff happening in the world around her and magically she'd start talking. Maybe that's the case for some kids but this one seems to need a bit more hand-holding and guidance. I'm okay with that. Especially when I can now claim she said Momma first while I was around, then Dadda (which we're trying to make into Dad-dy still) and Ba for ball is a close third.
She's also able to identify a lot more things when we read: ball, baby, bunny, apple, orange, dog, cat. And she can meow so there is hope for her still.
Moral of the story: Pay attention to your child's development and if there seems to be an issue or they are slow to develop, don't freak out. Learn what you can do to improve the situation and figure out what the issue is before you freak. In our case, I still think it's just another case of Ada taking her time and doing things at her own pace. At least that's what I'm spending all of my energy on instead of freaking out.