I think my objection to being called a girl dates back to the days when the male shop floor workers were called 'the Men' whereas, regardless of age and experience, female workers - shop floor, canteen or office were categorised as 'Girls'. I find waiters, etc. referring to a group of grown up females as Girls condescending to say the least. I will normally call them out saying 'I'm a Woman - W O M A N'
Strangely, or maybe not, I do not object to being called a Lassie, though my friend does and will state 'I'm a woman not a sheepdog'