Sounds like an infection of some sort. Could your daughter bring her to a vet sooner than Monday? Take her temp. to see if she does, in fact, have a fever? Has the dog now been brought inside?
Honestly, if the dog has gotten to the point where she's having problems getting up and moving around, it's clearly an issue which needs attention immediately.
In the longer term, perhaps sorting out the behavioral issues so that the dog can return to the type of life it was accustomed to would be a better solution than leaving her outside.