I like the Garnier Fructis hair products... for my daughter who has hair like your girl's.
We use the "length and strength" hair cream, which also conditions it. It is a leave in hair cream. It makes the hair very soft/shiny/tangle free and does not leave any residue. It just takes a small dime sized drop. Rub your hands together, then evenly disperse it with your hands throughout the hair and especially the ends.
This brand has other hair creams... which do the same thing.
Even Safeway has it, or CVS. Long's, etc. And it is not expensive.
http://www.amazon.com/Garnier-Fructis-Strength-Anti-Split...
Also, it is good and important to purchase a GOOD detangling hair brush.
This is the one we have, and it is VERY worth the price:
http://www.sephora.com/browse/product.jhtml?id=P241318&am...
You might also get her a satin pillow case... which helps prevent tangles. It helps my daughter's.
Also, trim her hair ends to get rid of split-ends. Or it leads to tangles and dry ends.
all the best,
Susan