Put the dog in a crate. Not only will she be UNABLE to get onto your bed, but when she goes to your parent's house, you will be able to take the crate with her so she will have a familiar place to sleep at the different residence. By crating her at night, you're providing her with her own "den" since dogs derive more satisfaction from small places than we do. She will more than likely put up a fuss in being confined beyond her control, but it should go away after a few nights as she becomes more comfortable with the crate. Do not give her any attention while she is whining, as this will only reinforce the behavior. Some people go so far as to buy earplugs for those first nights.
Introduce the crate in a positive manner, with lots of treats and praise. Put her bed in it so it has her scent in it. Feed her in her crate so she gets the idea that no one will disturb her and the crate is a safe place. When you have to shut her in, give her a special "crate toy." Many people have had success with Kong toys stuffed with peanut butter or cheese/liver paste and freezing these.
The crate is also useful for confining the dog when it can't be supervised to keep it out of trouble (see the first article above). My book, "Secrets of a Professional Dog Trainer!" which is available exclusively at Dogproblems.com, goes into more depth on the use of crates and other training devices.
About the Author
Adam G. Katz is the author of the book, "Secrets of a Professional Dog Trainer: An Insider's Guide To The Most Jealously Guarded Dog Training Secrets In History." Get a free copy of his report "Games To Play With Your Dog" when you sign up for his free weekly dog training tips e-zine at: http://www.dogproblems.com