Welcome! Have you heard of the Curly Girl method? There is information on the stickies on the newbies board or search YouTube or get the book itself. Techniques are at least as important as product selection.
Curly Girl: The Handbook: Michele Bender, Lorraine Massey, Deborah Chiel: 9780761156789: Amazon.com: Books
waterlily716 - curly hair & beauty @:-) - YouTube (loads of CG method videos)
Curly Girl Method for Toddlers (Kynnedy's CGM Detangle & Wash Routine) - YouTube (one of a series of videos on her little girl's haircare)

Several things to try
- satin pillowcase or satin sleeping cap plus 'pineapple' or braid at night
- switch from commercial shampoo to conditioner only washing
- use a leave in conditioner renowned for 'slip', there are several curly kids haircare ranges that will likely have decent products (Curly Q's, Ouidad Krly Kids, Blended Cutie, Mixed Chicks Kids, Kinky Curly Tiny Twirls)
- don't comb damp because you will damage her hair, either dripping wet and drenched in conditioner or dry starting from the bottom and working up (many curlies do not comb daily)
- may want to wash three times a week in order to detangle: this will be much less like hell if you follow all the above!

Detangling with fingers is gentlest, followed by a double row detangling comb. Some curlies like the Tangle Teezer brush. Those with thicker hair generally need to detangle in small sections.

Tangle Teezer the Detangling Hair Care Brand
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond/ fractionated coconut oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Au Naturale styling gelee
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect