Personally, in my N=2 where one is a male and one is a female, my female rabbit who I adopted at 1yo (vs. my male rabbit who I got at 8wo) has 1) superbly better litterbox habits (than any other rabbit I’ve interacted with, as a volunteer at two rabbit rescues, haha) and 2) goes out of her regularly to request pets from me while she lounges by my feet. Comparatively, my male (who again, I’ve had since he was 8wo and he’s now 5yo) is much easier to handle and agreeable to it; however, he tends to be more lunge-y and such when caught off guard.
In short, sex-generalizations don’t really inform individual, case-by-case scenarios at all, so they are practically not helpful. How your friend interacts and cares for the rabbit as well as learns about the rabbit’s personality and shapes it will be the primary and arguably largest factor in the quality of their relationship, as opposed to the rabbit’s sex.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.