I paid a deposit once, although I found most on here were very against it. If she got to pay for a hotel, then I don't think its unreasonable but would check reviews etc first. If it's an outcall to your home then should be no more than the cost of travel, if its more, then a red flag for me.
For me it worked out and had a good meet but be prepared for the fact you may not see your cash or her every again. If you're happy to take that risk, go ahead...