Ive been at the l'oreal acadmey for the last couple of days, and i asked about the box dyes regarding several treatments,(as they manufacture it and it was a colour correction module) and was told they contain 20vol. I was also told that regarding the scwarkoft live xxl shades are impossible to lift out,- it will only turn a orange the most. Doesnt matter how many times you lift it wont shift. As contains metallic salts, that allows it to gleam.
Ive had varied results from this service, the best to to neutalise the underlying pigment-by adding a ash then lifting from that, but still takes a while.
my advice would be to let her know it will take a while, proberly best if she has it cut out, we're not miracle workers! hths xoxo