Ramps New C&C cage w/ loft, pig blocking loft opening

I just got a 2x4 C@C cage with a 2x1 loft. I have 3 pigs in there, and they really seem to love it. I've had my pigs for a year (2 are 'babies', so March will make it a year), and they're still pretty shocky. The mother isn't shocky, she's laid back but isn't social, either. One of the babies is social and comes up to greet you, but as soon as you put your hand in the cage she runs. The other one usually won't come near. It's taken to sitting up top, where the ramp meets the loft. She likes it because it's mostly surrounded with walls, except for the opening to get inside the loft, which I have made into their kitchen. But she just sits there, and doesn't let the other pigs by her. If they manage to get up while she's away from the opening, if she moves back while they're up there they get trapped because she won't even let the other two jump over her. Is there a way I could stop her from just sitting in there? Thanks


Ignore the liner in the picture of the loft I gave, it's temporary while I'm finishing their real liner today.