How to remove dye from kids hair ?!?! Help please !!!

Anna 🥀🌙 • {24}SAHW 💍❤️ TTC our Rainbow 🌈👼🏻✨ PCOS 💙

So my brother in law has custody of his 2 kids and over Christmas break he let them stay with their mothers parents and sister well they dyed my 6 year old nieces beautiful blonde hair pink with out asking or even looking at her schools hand book 😡🙄😒 my brother in law is livid cause the school won’t let her come back from break until it is removed and bleaching or dyeing or any type of chemicals isn’t an option. I’m currently babysitting her while he’s at work she should be in school I don’t understand why she has to miss out of school for such a stupid mistake but that’s another rant for another post 😂 she’s sitting with baking soda and head and shoulders shampoo on her hair I don’t know what else to try it doesn’t look like it’s doing much please help !!!!