Need help with my dog?

my do is a female staffy/lab and has Always been extremely hyper she bounces at the door wanting to get in if i keep the door open for a Milly second she would be in she has 2 pure bred staffy play mates out the back with her but all of a sudden she doesn't get out of her lil bed she doesn't want food she has a drink and the older staffy try's and try's to play with her but doesn't want anything to do with him she is looking very sad and she's alwayss been a beautifull happy puppy dog so i have no i dear what is wrong im only 16 and ive had her mum since she was a pup and ive had her since she was a pup plz help im not shore what to do :'(