So you have 2 different issues here , forget about the cleaning right now .
Money wise this doesnt work out you took home aprox 33% of the takings ,
your earing 10% commission on products thats fare
the voucher so when the client redeems the voucher do you still get paid the 40/60 rate ?
have you seen her breakdown ? what is she deducting ?
is the calculations after vat & stock used ?