Rita
Dear Rita:
I would suggest crate training her. Not only will she be UNABLE to get into your bed, but when she travels to your parent's house, you will be able to take the crate with her which will provide a familiar place to sleep at while away from home. By crating her at night, you're providing her with her own space. She will most likely put up a fuss in being locked up beyond her control, but it normally goes away after a few nights as she becomes more comfortable with the new environment. Do not give her any attention while she is crying, this will only reinforce the behavior and lead to some very late nights. I have even heard of some people going as far as buying earplugs for those first couple of nights.
Introduce the crate to her in a positive manner, using lots of treats and praise. Place her bed in it so it has her scent, another good idea is to put an old shirt in, so she will have your scent as well. Start feeding her in her crate so she will get used to the idea that no one will disturb her and the crate is a safe place. When you have to lock her up at night, give her a special "crate toy." We have had many people who have had success with Kong toys, which can be stuffed with peanut butter or cheese paste freezing these will make for more of a challenge when she is trying to get the treat out of the center.