Why does my sister's hair smell like a snake?

She is 6 years old and her hair hasn't been around any snakes. She has been around about 2 wild snakes(garter) but hasn't touched them. Anyway...her hair smells like a snake's defense smell when it gives off that odor. My mom washed her hair really really good but the smell is still there. She used shampoo and conditioner. Is there a way to get rid of this smell? Thank you.