For going after feet, when Max didn't listen to the "no" command, I put him back in his xpen until he settled down. He would nip my feet when we first got out of bed in the morning. He learned if he wanted his freedom, no nipping.
For the come command, make sure you are calling her to come for desirable things as well as "undesirable." Tell her to come and reward her with a little petting and a "good girl", maybe a treat, and then let her go. When you praise her for coming, go wild like she has done the best thing in the world.
