What... she's not curled up on the couch? Well... I'm not a dog trainer. But I would suspect the way to teach Raven about the dog house is to put some yummy treats in there on a fairly regular basis until she gets the idea. She'll probably get the hint pretty quickly I would guess; & I suspect the rain aspect of it will probably take care of itself.

If Raven just doesn't seem to be getting with the program, though, perhaps another idea might be to get a chew bone & somehow affix it to the inside of the dog house when it rains. If the house is wood, you could put in a screw-eye & tie one end of a cord to that, the other to the chew bone so she can't drag it out into the rain. Just don't make the cord long enough that Raven can get tangled up in it.

By the way, I don't know if he's still writing, but one of my favorite dog-training authors was always Brian Kilcommons. If you're interested in reading up on the subject of dog training, I'd highly recommend his books.