Toning Down Hair Dye

She should wash her hair a couple of times with a detergent-based shampoo.

What kind of dye? There is a product she can get at Ulta or most big box stores called Color Oops Hair Color Remover==perhaps she can message the company before buying it....telling them the product she used and asking if their product can help.

I can't find a phone number, but their website is:

www.developlus.com/contact-us.html