You are doing the sensible things: enrolling her in Speech/Language therapy and undergoing a medical workup. Now, it is possible that she is 'on track' developmentally in her other areas and lacking only in the speech/language aspect of cognitive functioning. It's too early to know, but it is possible that she is displaying symptoms of a developmental disorder broader than the speech/language area. So, were you simply 'watching and waiting', I'd be urging you to arrange an evaluation. But you've already done that, and for now there's nothing additional to pursue. Just be sure that the evaluation focuses on overall development, not only on the physiological aspects of her development.
My daughter is two as well and is non verbal. She is in speech Therapy and has been since she was 14 months old. She has done well. We really had to encourage her to imitate. She now says some words and tries to speak much more than before. My daughter as well is able to identify objects and follows direction. There is nothing wrong with her hearing either. There are a couple of speech disorders that are out there that are very workable. We assisted our daughter in forming a sign vocabulary to combat the frustrations of her trying to communicate. Her sign vocalulary is very large. As she learned the signs we were able to see she was trying to say words at time they were just missing the most of the consinant sounds. We are very pleased with her progress and the sign has allowed us to understand her needs.
If i were you i would not waste time and i will take her to a specialist in autism, its better to be ahead and very sure that everything is fine. My daugther at 2 and years old knew many geometry shapes like octagon, count until 20 in english and spanish, ABC, ,color incluid caki color etc anyway her knowlodge like she was in kindergarten based on what the specialist said. Anyway when there is some areas more avanced than other very uneven is a characteristc of austism too, my daughter used to flap her hand on her face, she did not play with 4 toys in the right way, she knew the languaje but she did not use it, she always point what she wants but no using words. My dauther was diagnostic with PDD NOS because two specilist ( one specialist in autism and a developmental pediactry were not sure if she was in the aspectrum of autism or no, and they prefered diagnosted her that she could get behavior therapy soon and be ahead if there were some problem. I would say go to the specialist in autism because each child is diferent and the earlier the better. She was in the daycare where her teacher use to say that i was worry too much but i knew that there were something different in my daughter from other children. Now at 3 and half years old the specialist say that she is not in the aspectrum anymore by sure and belive me some children are so high funcional that is not easy diagnostic but working with them soon and constantly give result. Look for a institucion in autism closed to your home and also call to Early Intervention Program or Head Star so your child can get a free therapy at home before 3 years old. Good luck and sorry for my english is not my firts languaje.