@Shady41
I think that may be possible, but I figure the sister killed herself right after killing him due to yandere, and then would be born near him. As where the red head is actually a lot older than him, and would require her being reincarnated well before him despite dying afterwards. Also the red head hasn't shown any real yandere tendencies, like Dhammi has. I may well be wrong though.
@CraniumAmbiguity
A person doesn't have to retain their knowledge to be reincarnated, it could just be the same soul without their memories.