You've done the right thing in refunding the buyer, but you are WRONG on a number of counts.
1. if it was fake or looked to be fake I would mention that up front,
It doesn't matter if you mention it up front. The law, as well as ebay policy require that you NOT LIST unless you are 100% certain that any item is authentic. And if there is any question on authenticity, it cannot be listed. PERIOD!
2. she did not ask for numbers as I am aware and your right she should have done that first before purchase,
Again you're incorrect. It isnt' the buyer's responsibility to question authenticity. Any and every listing should be assumed to be authentic, since fakes (again, I'm repeating) can't be listed.
3. PLease don't relist the item, even with an authenticity disclaimer. You can't do that.
BeenBurned is totally correct.
The seller has the absolute responsibility of KNOWING the item they are selling is authentic - before they list it. The buyer is not responsible.
I'm glad you are doing the "right" thing and refunding your buyer. But you MUST authenticate the items BEFORE you list them.