Thanks all. I don't know if it was concern or hurt pride that led to my question. I think I misjudged the age of expolsive language growth and thought it was here and kind of anti-climatic, but really, I think it's still ahead of DS. I also may have been comparing DS to kids who are most advanced verbally rather than average.
These posts reminded me that my mother always said second and subsequent children speak later, which was echoed by many psoters, but I had forgotten that and assumed the reverse.
Thanks for the details everyone.
Advice and commentary on living overseas
DD1 15, DD2 12, and DS 9