This is some kind of a sugardaddy arrangement except that I don't know if you always have to pay upfront or not under that arrangement ( I have never had one).
In my opinion, the OP has seen this lady a total of 3 times which I think is not enough to build the trust level required to pay upfront. Also, he didn't mention the term, is this arrangement good for a month, 6 months or longer? If you could choose a month's term, and you can afford to lose that money, perhaps you could try this out first slowly. Another thing to consider is, if you can't see her for that month for whatever reason, would you lose that money?
In my opinion, the OP has seen this lady a total of 3 times which I think is not enough to build the trust level required to pay upfront. Also, he didn't mention the term, is this arrangement good for a month, 6 months or longer? If you could choose a month's term, and you can afford to lose that money, perhaps you could try this out first slowly. Another thing to consider is, if you can't see her for that month for whatever reason, would you lose that money?

