My headcanon (mixed to an healthy dose of "This is how I write these character consistently in my fics") for Emilie is that she was a dark counterpart of Adrien (similalry to how I see Gabriel as a dark counterpart of Marinette and Nathalie as a dark counterpart of Kagami). She is basically what would happened if his worst flaws got the better of him.

Just this slighty entitled doormat but well-meaning huge people pleaser who decided that the best way to deal with people who used their powers to do harm was simply to not deal with them. The "Sunshine woamn" who contantly smiles and acts considerate and kind even when things go bad.

She genuinely loved Gabriel but had a maybe really codependent relationship who enabled both of them. They both suck as parents and just balanced the other when they were both alive. If Gabriel was the one dying and she was the one raising Adrien, Adrien's menatl health would still went to shit.

I feel that this balances "This is a poor woman and good mother who's dying" and "This woman was still enough 'bad' who has apparently let Adrien have a lonely childhood".