I'd inform her in an email of the situation. I might include a pdf of the invoice so that she can view from her phone if she decides she wants to. And let her decide how to handle the situation. Better to let her make the final call than to have it be a big deal and it be on you.
But that is it.
Mix of 3s, thick, coarse, medium porosity
Current hair styling technique: rake with a scrunch at the end. (works with my coarse hair)
Known HGs: KCCC, homemade fsg, honey