Hi there,
I second the
KCCC as I use it on my daughter who has very fine tangly delicate 2c curls (the hardest type)
KCCC makes her hair really curly, and helps with the frizziness, to shampoo I use
Jessicurl HCC or
Kinky Curly Come Clean for Conditioners I like
Biolage Conditioning balm or
KBB milk and for a leave in I use
KCKT (I use with
KCCC)
KBB milk Or
Biolage Conditioning balm (so I can use the same conditioners as leave ins!!) I would try the same products on both their hair and see how that goes, you may find something works better one one and vise versa but its really trial and error, going CG and cutting out silocones and sulphates has improved my little ones hair