I use 2 bands, in addition to the bow. First off, gather the hair that's going to be placed into a topknot and divide it into 2 sections -- a front and a back. Wrap one band around the front section, followed by the bow. Then gather the back section, combine it with the front section and use another band to hold the hairs in place.
If her hair isn't long enough for a topknot yet, you can always do piggy tails
