Her character page mentioned that it is unknown whether she was Albus' maternal or paternal aunt. I thought about it and I realized that Kendra Dumbledore was a muggleborn while Honoria was a witch.It's not impossible for there be more than one wizard/witch born in a Muggle family, but from what we've seen it's pretty rare (Colin and his brother are the only example I can think of), so I'd say Honoria is most likely Percival's sister( I can totally see the same set of parents coming up with both of these names)