When my first son was young the checklist at the MCHN for 18 months was 10 words. There were some children in our mother's group who could barely get that many words. If you included making animal sounds they almost made it but they had more like 6-8 words. My son had over 100.

Fast forward to 2.5 years old and my son was developing a significant speech delay because he didn't start making 2 word sentences. The children who had just a few words at 18 months were doing fine and continuing to develop their vocabulary and expressive communication.

So I really wouldn't be concerned at this point. It is more important that she is communicating, even if non-verbally or with utterances, than her total word count at the moment.