She is old and fat. Sorry but it's the truth. Sir Mo does not speak a lie.
Old, fat and I'm fairly confident her womb no longer works.
EDIT: Magnus must wake up in the middle of the night, role over to look at her old saggy face and think to himself... "What the fukk have I done?". He quietly rolls back over as to not awaken the beast, and silently sobs into his pillow, knowing he punched below his weight.
Dang that's rude as hell. She's not even 40.