Polar bear, your response doesn't worry me at all smile I'm happy to have others who can Ivcan talk to about this stuff and give their experiences.

Like your DS, DD3 didn't babble a whole lot as an infant. People would always comment on her extreme observant behavior when we were out. We also knew by what we asked that she understood what we were saying but before 3 thought she chose not to talk. She talked but not as much as our DD7. We wondered if DD7s intensity and constant talking caused DD3 to be quiet. As well as DD3 being very good at expressing what she wanted non verbally we thought maybe we didn't give her the chance to talk.
She is doing very well with ST (she scored 1% for expressive but were told that her age is a factor being right at 3)and we have the option to put her in the local preschool program for delays. I haven't yet and read a thread about it and question whether I should.
I looked over a lot of threads and one stuck out about preschoolers with anxiety. The SLP also asked if DD3 has anxiety out of the home and I never gave it a second thought. Now I feel like maybe she does as when home she is vocal, even if not understood well, intense and so sweet. She is very observant and change seems to be a little hard on her. She doesn't like being away from me and DD7 is definitely a safety blanket for her so to speak. I worry that if I place her in the preschool program she won't participate at all. I know for sure she'll tantrum at drop offs (tried regular preschool at 2 for 3m and she tantrumed every drop off). I know private and preschool therapy works great but I worry about her. She is doing so well privately I don't want to reverse anything.