There's no legal reason you can't do whatever you want.
There's also no legal reason for your mom and sister to let you keep living there.
The worst-case scenario is that your mother kicks you out of the house. Which, in my opinion, wouldn't be a bad thing for you if they do this because they're upset you went on a date.
You only live once
“Fiorenza” is an archaic or poetic form of the name in Italian. This version was commonly used in older Italian literature and poetry, including works by Dante Alighieri.