You have paid your money and that entitles you to full access of everything on an escort's likes list for the time of your booking ; you do not have to wait and see if she offers , just ask her for it .
A couple of posters are suggesting this, which is being slightly unfair to the OP. It's not as if he didn't ask for sex - he did and she refused.
i was hoping that she would let me get inside her but she was unsure because of my size
However, he should have been more persistent and demanded sex or a hefty refund - as he himself admits.
But that doesn't excuse her behaviour in the slightest.
She's in the wrong game, but unfortunately, there are enough fluffies with more money than sense.
I see on UKE, she reckons only 10% of her punters have heard of UKP, which is probably true and, for her, just as well.