I'm inclined to let know it alls be know it alls, it's a fitting punishment. If her lack of hair growth isn't enough to get her to open her mind, I wouldn't waste my breath trying to convince her that she's wrong.
If she asked why she couldn't do my hair again, I would simply say her methods are bad. I'm a blunt person.
3C/Fine to Medium/Low Porosity/High Density
CJ Gentle Cleansing Shampoo
DB Pumpkin Seed Curl Moisturizing Conditioner
CJ Smoothing Lotion
Queen Helene Sculpturing Gel & Glaze
No Salts, No Waxes, No Butters, No Heavy Oils
No ACV, No Saponified Oils, Protein Sensitive