SPD cause speech delays?

My 22 month old daughter is not talking. she has been in speech therapy with ECI since 18 months old and she can now say about 6 words (ball, book, uh-oh, cat, dog and no) and these words have only come about in the last month or so. she only says them sometimes, if i pick up a ball and ask her what it is, she will only look at it and me. but then ill just be sitting there, she will look outside, see her ball and point and say "ball". her therapist said based on some things she had noticed that she thinks she has spd and we are waiting on an occupational therapist to evaluate her.

Can spd cause this speech delay and will her speech ever get better? we have friends with kids younger than her by a few months and the difference is very noticeable. one 20 month old was actually communicating with 2-3 word sentences and i felt she understood everything i said. (sometimes i feel my daughter doesn't grasp what im saying, either that or shes purposely ignoring me) Any advice would be greatly appreciated.