Until I came across Mumsnet I didn't realise 'ladies' was an offensive word. I'm old, you see, and when I was brought up, 'ladies' was the polite word for any adult female, while 'woman' was rather rude. Or perhaps that was just my mum, who was a stickler for the rules. Oh, and my home-counties all girls grammar school which had pretentions of grandeur.
Anyway, I consider myself a lady, as well as a woman, and I'm happy with that!