She may enjoy the sensations of being petted. Mine seem to like rubbing against things and the rubbing combined with the heat could be pleasant for her.
I've noticed that there are two sides to the question of whether a BP likes something or not. Generally, the pet-type owners tend to have more of a tendency to read behaviors as enjoyment or trust or bonding while the business-type owners have a more pragmatic view and see it as just instinct. I think it may be somewhere in the middle. I think our BPs can learn to recognize us and trust us. I don't think they have the capacity to love us like a dog does. She's probably seeking the heat from your hand, but she may also be enjoying the heat and sensation. We really don't have any way to know for sure. I've noticed that my snakes tend to display preferences and have personalities. For example, my male spider is comfortable being handled by almost everyone while a female spotnose I used to have showed a very clear preference for women and would strike at men every time, but never women. It was probably the difference in how men and women tend to handle animals. Men tend to be more heavy-handed. My pastel seems more comfortable with a firm grip while it stressed my spotnose and my female spider just plain doesn't like being handled, but my ghost will sit with you as long as you want. My males also seem calmer than the females. So I can't believe that they're pure instinct and don't have preferences and personalities. Otherwise, you'd get the same reaction from every snake to the same stimulus.
Does she enjoy it? Possibly. If she seeks it out rather than stressing or trying to escape or strike, then she's most likely at least comfortable with it.