There are some issues here.
A key problem seems to be that she gave up everything about her previous life, to become a member of the royal family. She apparently didn’t appreciate that her job was being a member of the family and representing the family at public events. She didn’t realize she had to sit down and shut up and be a good duchess, to live in seclusion and had to ask permission of some unknown individuals in The Firm to go out to lunch with friends.
And it seems she doesn’t have the type of personality and demeanor, to accommodate herself to everything that was expected of her.
She was in the television industry. She could have watched The Crown. It became apparent to Elizabeth from the time of her father’s death that “the family” was run by a professional staff whose mission was to serve and preserve the monarchy. Meghan should have known that’s how this family operates and if it wasn’t for her, turn down joining the family.