should I be upset at all?

Skylar • 5 angels. 2 beautiful daughters♥️
I just left my field of cosmetology to try and get back into childcare. I applied at a daycare, went in for a interview, did a visit, shadowed and have been working there for 2 weeks. I have tattoos on my arms, chest, and hands. I'm at home and I get a message on Facebook from the director of the daycare telling me I need to cover my tattoos at work and that it states it in the rule book and she'd be happy to go over it with me. 
I understand I'm the head teacher of 3 year olds. However, if it was an issue before, shouldn't she have told when I started 2 weeks ago? I was never even given a hand book to read. It's not a surprise that I showed up to work and poof I had tattoos. 
It also frustrates me that instead of emailing, calling or talking to me in person she took time to message me on Facebook.