My scalp is extremely sensitive!!! Relaxers have always burned within minutes of it touching my hair! A few things have helped:
1) Washing more frequently. The more I wash, the cleaner my scalp is, the less I'm likely to scratch. If her scalp is dry, tell her to try Flaxseed Oil.
2) No exercising 48 hours before a relaxer application. I was always good for working out then getting a touch up the next day
Dummy! Burns from open pores..
3) No washing my hair three days before a touch up.
4) Avoiding carbonated beverages the day before a touch up.
5) Try Vitale Life and Body with Aloe. It's lye, but I've never had a burn after using it.
She might want to consider the fact that she might be allergic to relaxers which is not uncommon. In fact, I thought I was allergic and vowed to discontinue usage if none of the above worked.