You could try camomile tea before bedtime or the celestial seasonings sleepy tea with valarian in it.
Maybe something with some lavender essential oils in the room or even a bit of a massage with a teeny tiny bit of lavender in the oil (you might be able to buy a lavender scented massage oil).

ETA - just saw her age. She might be a bit young for herbal teas Then again a tiny bit of camomile tea can't be worse than some of the infant medications out there.