50-50
I agree with most of what the responding posters have said: the girl may like sex a lot, and she may like you a lot as well. But: you met her in a sex-for-money context, and its' not like she is hurting for sex currently
.
I have made "friends" with some of the girls to varying degrees of success: spending time at my place or out on the town, talking about things they don't have other people to talk about with, etc. A retired agency escort who became my friend told me: "you are the only client I would like to keep after", and she only charged me what the agency was paying her. Believe me when I say I made sure to treat her extra-nice. A couple of times, some asked for my professional expertise and hopped in the sack with me for free after to say thanks (I had not asked)
. But even then, it was understood this was an exchange of services.
One of the friendships I enjoyed the most was years ago, before web-based advertising: my lady friend at the time would come to my place a few times a week and wait with me for calls to come in while we'd socialize. If I felt horny, all I had to to was ask, and the "clock $" would start ticking.
If you are nice, non-judgmental and easygoing, its' relatively easy to befriend ladies in the business, they are just like anyone else.
The bottom line is that like with any professional, friendship is possible, but business is business. Mix in the very personal aspects of sex, sense of self-worth and the way you initially met, it makes for very careful going. Of course, if the lady begs for you to stop paying, that is another thing altogether. But it is my belief it should always come from her.