Newflvr, you needn't worry about Catherine "ruling the roost."Â
 My parents don't put up with much nonsense from the six of us.
Sometimes, particularily in the evening, we are all busy and Catherine isn't watched as closely as she probably should be. That's when she has the opportunity to do this sort of thing.
PrincessnMI, thank you for mentioning those! We hadn't heard of them before and will probably try some.
No Dog Now...
 I honestly don't find this humiliating, just frustrating. Maybe I would if she was still doing it in a few years, but I don't think that she will be.
Catherine hasn't tried anything today so far (or last night after I posted); she's temporarily forgetten I think.
Sofia