rivka

No, it's not reasonable for her to demand it. By the same token, though, if just her being up and around during her awake time ever disturbs you, it would be just as unreasonable for you to demand night-time quiet. She got rid of the partner, so the fights aren't an issue anymore and weren't entirely her fault to begin with. This is a situation, in my opinion, for being as neighbourly as possible on both sides; it's not like you can expect your neighbour to take a daytime shift to make your schedules compatible. She may well do that out of sheer sleep deprivation if she never gets a full day's rest, though. :/ I guess you can hope she does that or that she moves, but that's about all.