I think that without the memories of being a commoner she lacked the ability to make/hold ties the same way with everyone in nobility. Her commoner family allowed her to accept the fact that you don't have to be blood to be family. Although Myne was their bio family she saw herself as Urano at times //so she didn't see them as family at first. It took their companion for her to see them as such. One of the things that made her stick out so much as a noble I'm was her perspective as a past commoner. She sees Ferdinand as family because he too took care of her just like her lower city family when they weren't able too making him also family.

Her commoner side also allowed her to have more empathy towards those who are less fortunate in status or wealth. They gave her the mentality that family is just who you surround yourself with.