Mckay123,
It is obviously not normal for an extremity to swell. You do not say if she injured it or not. Or if the swelling just showed up.
In either case, you should elevate the limb, apply ice and compression. An ace wrap from the toes to the knee should be applied evenly.
The numbness and tingling could be just from the swelling. Or may be a problem on their own.
If the swelling does not go down shortly, it starts to get worse (going up the leg), your mother develops discomfort in the limb, or there are other symptoms, she should be seen by a physician.