How about just eliminate pronouns altogether. Don't see any reason are such an essential part of language. Just don't use pronouns at all. Why can't all just agree to? 's not like are even nessecary.
Change all of these people to male and you still have the same problem. It is just nitpicking to come up with very specific circumstances where it may come in handy.
Why don't we create pronouns based upon hair color instead? Dhe for dark haired people, rhe for redheaded, lhe for light haired.
That way if we talk about the Spice Girls, you know who I mean when I say "rhe had the best voice"
Jack, Jill, and John went on a walk. The group found an apple. Jill ate it. A farmer yelled at the group.
No need for pronouns when avoiding the usage is possible! Some sentences start sounding a bit weird though. Would writing a book be possible in this manner though, provided the text should remain understandable?
I hope I avoided all pronouns above,, it's really difficult but kind of fun.