Should we be keeping her locked away or should we have her in the room with us and teach her not to jump/push?
Personally if it was me I wouldn't lock her away, I'd teach her not to jump up.
Have you taught her a " down" command? billy used to be a swine for jumping up at the worktops and taking a swipe of food
, I taught him "down" & he's fine now. every now and then he may push his luck and put his paws on the work surface but I just point at the floor and he knows to get down.
Do your children give her their food? If so then I'd put a stop to this right away, as if she thinks she's likely to get a crisp or something then the more ikely she is to beg and try and steal the food.
Is she hungry a lot? what do you feed her?
I had a dinner party once when Billy was younger. Before asking people to come and sit in the dining room i put a nice hot freshly baked bread on each side plate. Two minutes later when everyone was sat down OH said to me "where is the bread" ( I was in the kitchen at this point) so I shouted back "It's on the side plates" he replied " erm no it's not"
billy the greedy monkey had stolen 6 breads in the space of around 4 minutes !