How to sack someone really nicely?

okay right this is going to sound weird but bear with me. okay we pay a cleaner to clean our house once a week, she is not ery good at it, always finding oads of cobwebs and dust she never mops and bearly hoovers. we dont have enough money to buy food let alone pay for a crappy cleaner its got so bad that i am haing to pay for food from my money whih i get from my paperround. ive tried to tell my mum that we should sack her and that i would not mind cleaning myself she keeps saying that i have enough to do already then she says stuff about not knowing how to sack someone ive tred to tell her how to do it nicely i said "just tell her that we dont have enough money to keep her going at the moment" plse can you give me some advise please.