Very fascinating. I assume it’s a topic that has already been explored but if not it could be illuminating to do so.

Other recommendation is to explore gspot stimulation with fingers/toys and anal stimulation if she is into it.

Ultimately though don’t worry too much about this if she says she is satisfied. But the lack of clitoral stimulation could require some medical investigation. Something like her hormones could be off.

Not a woman but a good question to think about is can she orgasm through masturbation? If so ask her to explain and/or show you and incorporate it into your play time