I don't think she would be. She seems like a really friendly person; someone who you could always talk to. I think she, Princess Astrid and CP Mathilde would be the nicest people to have as mother-in-laws.
You have brought up one of my worst fears; having an evil mother-in-law. I won't say too much (to protect people's identities *lol*) but I know that if you do have bad mother-in-law, it can be hell, but, it does provide hours of entertainment arguing/abusing/criticising them behind their back.
Danielle =)