TripleDaisySummer
I suspect she'd be quietly furious carefully spoken words to convey her deep anger or a few dark mutterings to well known and trusted staff members to get it off her chest.
This seems more likely to me too. I suspect someone so used to having staff around would keep their emotions restrained until they were in private with friends and family.
However, MN tends to be a place of high expressed emotion (eg people "scream" rather than "shout" or just "raise their voice"), so "angry" becomes in people's minds "a rant" and "as angry as I'd ever seen her" becomes "the angriest she'd ever been in her whole life" etc