I second what Tevyes Dad wrote. The more you can help get the weight off the leg the more you may be able to soothe it. It is vital to know what's going on - if it is a foot injury, splinter, bumble, or possible pulled muscle. I like to give mine treats after checking them out, so they will associate treats with being handled.
An Epsom salt compress can help with a pulled muscle - don't let her drink it, it's a laxative. Just put Epsom salt and water solution on a clean rag and wrap the foot and leg, hold it for as long as possible, up to ten minutes.