To be honest I think mozuya environtment are toxic. I know they tried to considerate with her, but it make the condition worse.
I Think near a people like the black haired lady(her old friends) make her condition better.
And I just noticed that actually she can act really normal around people...
Its complicated because if she is duke's daughter, she can live with him but it will tarnish his reputation.
But If she is not, she must spent 18 years in cage with her uncle.
To be honest I just want beat his uncle and the emperor smug face.