First rule of being a son or daughter - your parents won't listen to you! Will she pay more attention to your brother or another family member or friend? Failing that, make an appointment for her, tell her you are taking her to lunch but take her to GP's first - sneaky but might be effective?!. As a 'moley' person myself, I keep an eye on my moles and they do change shape and colour with time but the one's I've had removed have all been OK - you can tell your Mum that if you think it'll reassure her. Also having them removed is not painful or complicated. Parents eh!