I disagree with you when you say she knew exactly what she meant because she repeated. I bet if you'd known the phrase and said "You think I'm a prostitute???" she would have said no.
Re moving the cash till.
I know you don't want to think it might be racist, and there's a chance it isn't and I'll tell you why, because this also happened to me. I was new to a school mum friendship group, and when they went out they always had a kitty, everyone used to go to the bar with the kitty purse in turns.
On my turn, the self appointed 'leader' gave me a grave speaking to about how much was in there, that it had been counted etc etc., I was a bit
but went to the bar, after I was done I returned the kitty purse with receipt! About an hour later this silly bint started openly accusing me of stealing the kitty purse, she couldn't find it, so I MUST have stolen it... it was all very upsetting. She found it 10 minutes later in her bag.
It could be that this woman is JUST a twat, that your race has nowt to do with it, maybe it is racial - either way the woman was being a twat.
You have to find it funny else you end up miserable or thinking everyone is that bad, you know you don't look like a prostitute, you know she was BU, and so does the lady who was there too. Try not to take it to heart.