*My first suggestion would be to increase the amount of combing conditioner you are using in her hair. It sounds like you might not be putting enough in her hair. Try to leave in too much. You might even put in two full handfuls into her hair--one handful per half of her hair if her hair is shoulder length or longer. When I say use lots more of the conditioner, I mean so it's glopping out of her hair as you comb, and even looks white when her hair is still wet, it should be enough. If, when her hair dries, there is any white left, simply smooth over it with a bit of water in the white places, and you are done.

*I'm sure you are already doing this, but do leave the combing conditioner in her hair. But it was leaving in that conditioner that's made the biggest difference in making my hair hang down instead of puff in humidity.

*Make sure you are defining her hair after combing it. If she has places that are extra curly, like the top back of her head, you may need to make very small curls to smooth.

*I'm not sure how long her hair is, but putting it up at night is very important. If her hair is long enough, put it in one (or more if needed) braids or buns at night and sleep on them, will help stretch out her curls. Make sure when you braid her hair that you gently but firmly stretch out all her curls into the braid. Do not finger comb, brush, comb or separate her curls at any time (unless it's time to comb her hair again). This step makes a huge difference.

(After washing, combing, defining, and letting her hair air dry without disturbing her curls, braid her hair up firmly (without pulling too tightly--but making sure all her curls are stretched out gently into the braid) when it's dry as well. )

*After she sleeps on your hair overnight, then undo it in the morning and don't comb, brush, fingercomb her hair, and her curls will look more stretched out.

In the morning, you don't have to wet her hair to refresh if you don't want to. Maybe only lightly wet her hairline or any fuzzy parts. Especially if you've put her hair in braids at night, she may get a bit of the wavy braid texture in her hair.

If you're washing her hair about once a week, and if you braid up her hair every night, it will hang longer and longer as the week progresses. Or, you could smooth on extra conditioner in the morning to keep her curls clumped together and heavy. Since water helps our curls spring back up (which I love, but if what you want are looser curls), refreshing her hair less often or not at all between washes, and braiding it at night (plus leaving in more conditioner when you do condition it) will keep your curls stretched out.