Surprisingly, she did not bust out with 50 words during the evaluation. In fact, in the space of 2 hours she did not utter a PEEP until 1 hour 45 minutes in (and then it was all babbling/jargon except for a few recognizable "uh-ohs").
However, after a developmental eval and a separate speech eval (which were mostly play-based and based on my answers to questions about what I've seen/heard her do), she is generally at her expected age, or within the 25 %tile in some areas (like fine motor), which is not enough for services. They decided to adjust her age, since she was about 4 weeks early, so instead of evaluating her as an 18 month old (which she will be on Monday), they had her as 16 months, 23 days. Whatever.
So, the long and short of it is that her receptive language is in the average range (as a 16.23 month old), and her expressive language is at the 12 month level. We got a nice pat on the head, and were told that if by 24 months (when they stop adjusting ages for prematurity) if she wasn't at 40-50 words, to call them back and schedule another eval.
Hmm... that would sure be some language explosion, given that at 18 months she has 4 words. But again, fine. We'll play.
Hopefully I'll be updating this in 6 months to say that Maddy has met that goal!