M.S.
YES!!! You must keep her away from other children. Although rare in adults, they can get it to so don't share drinks/food, etc.. Your Dr. didn't mention how contagious it is? Since it's been 4 days, at the most 6 more. 7-10 days from start to finish or when sores are healed on hands/feet and gone from the mouth. Both of my kids just had it. Nothing you can do but if she gets the sores in her mouth, they will hurt and you'll want to help her with that. No acidic foods. To help numb the pain (if she gets sores in her mouth) 1:1 ratio of kaopectic and childrens liquid benadryl (SHE WON'T BE INGESTING THIS - but it is safe if she gets a little) since she is too young to gargle and spit out, put this mixture on a cotton swab and just go over the sores in her mouth. It won't get rid of them, but will aid in healing and help with the pain.
Hope your daughter is feeling better soon. HFM is VERY common.
M.