Hi Megb!!
My DD's go to cc (from ~ 9months) and DD1 has had big separation anxiety issues. Having said that she is generally fine after I leave and if DH drops her off there are no issues.
We have always been very honest about the fact we are leaving and make a point of saying goodbye and going promptly after making that point - sounds silly but the prolonged goodbye makes it worse for everyone. I was advised that whilst sneaking out is easier on me it would make her less confident in me.
I have known people whose kids were upset at school still and that is really unavoidable unless you are up for homeschooling......
I guess be guided by the staff and see how you go. I definitely think explaining to her why and how things are going to work may help too.
Good luck!