A few I can think of:
loads of leg lifts
hang in pike and hold toes by bar (don't touch the bar with toes though)
Hang in pike as above but push legs towards ceiling and back down again, all the while holding legs against the bar
Have DD Lie on the edge of a bed on her back, so that her legs are not touching the bed. Hold arms straight by ears (she will need to hold a stick or broom handle to mimic bar) lift legs up in the air, then over the head so toes touch the stick. Push ankles into the stick she is holding and sit up, keeping stick in contact with legs all the way up. she should end up standing in a dished shape, with the bar by her thighs. (This is basically the action of the kip - doesn't require strength but helps with understanding the timing.