Yeah, i was told that she felt guilty that's why she let herself get cursed and it kinda made me unsatisfied.
However seeing her guiltly feeling first-hand makes it more understandable why she'd just not explain anything at this point.
Trying to explain herself, to her, would feel like she relegating blame and dismissing his and their son's suffering
It would also feel like she's trying to make herself feel better by not being at fault (which she isn't but self blame is one hell of a drug, that you actively need an external force to tell you that you are not to blame)

Yahhhhh, though it is frustrating that she didn't give an explanation, I can understand her. She's feeling so guilty and this is a bittersweet ending for Yandere x Yandere (FL is possessive and it was shown/hinted in her thoughts)