To tell or not to tell... (CP)

My 36-month-old (former preemie) has motor delays.

At this point, my child does not obviously appear to have delays/disabilities.  There are some comments about how cute their toe-walking is and things like that.

My child will start a dance class next month (at least in theory).  Should I say something to the teacher (which could influence the teacher's perception of them) or just let my child in the class without warning the teacher that my child does not have the motor skills of a typical 3-year-old?

Likewise, I am preparing myself for a mild CP diagnosis.  I know that I might have to take some time for myself to process.

But then...  I always knew this was a possibility and tried to keep close family in the loop as to developmental delay.  I have not specifically said CP to them.  Partly because I didn't want to sound overdramatic and partly because I fear insensitive comments.  

How should I tell my family?  A mass update to everyone just laying it out?  Making a point to tell individuals personally (this would be easiest for them)?  Not saying anything until they ask?

I just want everybody to treat my child the way she deserves to be treated.  I would love to know what communication strategies have worked for others.