Generally speaking, if she is not putting any weight on the foot at all, that is, she is totally carrying the leg up when she walks, that usually suggests a more serious injury. Assuming the injury could not be result of a more major trauma (like being hit by a car), it is okay to watch her for an hour or two to see if the lameness changes. If the lameness is caused by something like a bee sting, she may be nonweight bearing initially, but often the lameness will subside if you give it a little bit of time, but if she continues to be non-weight bearing, I would recommend not waiting until Tuesday to have her seen by a vet.
Most vets have some arrangements for handling after hours emergencies. Depending on the size of the community you live in, it may be that they can meet you at their office after hours or they rotate emergency call with other area vets or there may be an emergency clinic in the area where you can take him. If you call your vet's office, you will probably get a recording telling you how after hour emergencies are handled.
If for some reason you cannot get her seen before Tuesday, you should keep her as quiet as possible through the weekend. She should be kept indoors and be taken outside on a leash only long enough to go to the bathroom so that she does not worsen the injury. If you can see any wound on the paw, that should be cleaned with water twice daily.
If she gets better on her own and doesn't require an emergency visit, you may want to call your vet on Tuesday and ask about how after hour emergencies are handled, so next time you will know what your options are for getting emergency care.
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