If you are no longer interested in interacting with her because she won’t sleep with you, then just stop interacting with her. A good way to do this is to just tune her out when she’s talking to you. Nod, make affirming noises, but think about something else. It’s not worth getting rude over. As soon as you can, make an excuse, exit the conversation, and leave her presence.
If she talks to you again, do a repeat performance. Eventually she’ll get the picture that you’re not her friend and she’ll move on. Don’t feel like you’re obligated to get personally involved if you don’t want to.
Personally, I think female friends are great, you get an awesome perspective of what it’s like to be on the other side of the chromosome divide. I generally only have female friends that are attractive. Good female friends are aware of the romantic / sexual tension and will work with you to avoid hang-ups.
The not-so-great ones will bombard you with sexy pics and then act surprised when you tell them they’re leading you on. Learn to recognize which is which and avoid the users, at least until your boundaries are such that that sort of thing rolls off your back.