I don’t think you will be successful in bonding these to unless you get your girl spayed. She is humping the boy because her body is telling her that she needs to procreate (have babies). The boy is of course not interested since he’s neutered.
Sex-drive is very strong in rabbits, in boys and girls alike. She will not be taking any hints. It’s not her rational mind that’s telling her to behave like this, it’s a very strong, hormonally driven sexual urge that’s making her do it.
I recommend you to separate the two, like you seem to have done, but keep them so they can see and hear and smell each other. Then make plans for having Snuggles spayed. Find a good vet that has done many spays before. This wouldn’t be considered unnecessary surgery. It would enable your two buns to bond and become a happy, bonded couple. Girl rabbits should be spayed for health-resons alone anyway, since intact does have a very high risk of getting uterine cancer at around age 3-4 years.
It’s very wise of you to have separated them, you should not force them to be together, when rabbits fight for real it can get really bad with substantial injuries to both buns.
If you like to you can post what general area you’re in (no specifics) and maybe some members know about rabbit-savvy vets in your vicinity.