It is illegal to not offer a receipt. If your provider refuses to offer one, she is probably not claiming her daycare income and therefore not paying taxes on it. I'd demand a receipt, as it is your right to have one. You are entitled to a receipt for all daycare fees paid. It doesn't matter how you paid (cash, cheque, emt, whatever), and it also doesn't matter if she is a registered business or not, as home providers are not required to have a BIN.

I have seen advertisements from providers offering a lower price in exchange for not offering a receipt. This is also illegal, as it means they are not claiming the income from the clients that aren't given a receipt.