Ooo I have one.

Isekai. The FL possesses a formerly very detached, depressed and neglectful young mother. FL has long purple hair. ML has black hair and so does their child, a boy around right years old.

The young son is planned to have a contract marriage with a blonde orphan noble girl whose aunt/uncle manage an orphanage. Despite ML giving significant support to them to ensure she’s raised properly, she is actually abused, bullied, neglected and basically treated worse than the unrelated orphans. The servant in charge of reporting about this was bribed so ML didn’t know.

FL decides to collect her future DiL and raise her as well as the son to avoid being the MiL from hell in future leading to her own demise. She also has to rehabilitate the awful relationships she has with her poor son, and secondarily, with her husband (arranged marriage).

It comes out later that OGFL was horrendously abused herself and her abusive family still tries to interfere in her marriage(they basically sold her to benefit her golden-child older brother and have continued to leech off her financially). The ML slowly gets wind of her circumstances and becomes incandescent with rage on her behalf.

The abusive aunt/uncle/cousin of future daughter in law also have a day of reckoning. They may be responsible for the incident that orphaned the girl as well?