Sorry OP, women our age think a little differently. Sex talk can be taboo. It has to do with the times. Natural has very little to do with it. Patience might get you there, but maybe she has difficulty being with a girl. I can't say, but as previously mentioned couple's therapy might help.
Cynthia, I am so sorry sweetie, we went down the rabbit hole. This is the path less traveled. Trust me when I say, and this is for everyone of every gender or sexual orientation, two people connecting sexually on the same wavelength is rare. It could be as simple as she does not feel attractive. Youthful hormones make it seem so easy, it's not. On a positive note, I was able to satisfy my ex for years after I was unwilling to use the penis, if the love is there you will find a way.