As a ballet teacher- just please do not buy the Wal Mart, Kmart or Payless ballet and tap shoes....they are plastic and although to you they may seem harmless- they are absolutely horrible, badly made and even for dress up can damage your childs feet and cause cramps in their feet... all the parents of the kids I taught would cut corners by buying them and their kids would have to take them off and take class barefoot because they hurt them so much and cut their feet up.
I recommend visiting
www.discountdancesupply.com and buying some real leather ones with a cotton lining...you can get them for about $12 for a child. Sharing something like ballet shoes is not recommended as their feet sweat horribly in them so it is really not sanitary. I recommend buying the brand Bloch....they are a good fit for little feet and are made well- (won't fall apart after a week like the Wal Mart ones) I actully wear Bloch shoes myself. If you buy good ballet shoes they will last a lng time also as the leather stretches and forms to teir feet well. If she wears them so much that she will wear them out you do not want her in plastic ill fitting shoes for hours at a time...
This is something I know a lot about and I am just giving you advice of what's best for her feet and your wallet...I'm sure a lot of you think it doesn't matter but just trust me...I am a Royal Academy of Dancing teacher and I do know a thing or two :twocents: