Help!

Okay, so this is a question for mamas of toddlers and up. My four year old has an appointment tomorrow morning with a developmental specialist that is going to assess her overall progress and abilities to see if she qualifies for school district covered pre-K as well as other programs that would benefit her. They've already discovered she has an astigmatism (which we will be getting further looked into) and are continuing to look into anything else that could make her struggle in school.

Tomorrow is when they will be doing speech and academic-related assessments and today she lost her voice to the point where it's cracking frequently and isn't really as talkative as normal. My gut instinct is to call and let them know that this is going to interfere with her ability to show her speech skills and reschedule. Or am I being a little too worried?