The trigger for my elbow patch of atopic eczema was shampoo bubbles
running down my arm, took me years to work out why it flared at work (blamed air con) and nights out (blamed alcohol). Went to conditioner-only washing and it healed within a week, that was over two years ago!! Have 'spoken' to many others on forums and IRL who have also had great improvements in their dermatitis on quitting all sulphates, including my own mother.
Note that sulphates are in box dye and toothpaste, not just the obvious shower gel, hand wash, shampoo and dish soap. If your daughter can, I'd recommend avoiding all anionic surfactants, certainly going to products that are pH 4.5 (ideal for hair) to 5.5 (skin). Fingers crossed she gets some improvement.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.