I must be the only one, although I appreciate everyone's comments, who can't really see the problem. Yes, it would be courteous to ask, but she didn't, and in all honesty I probably wouldn't have even thought about asking either! Not because I don't care about or respect your feelings, but because I just wouldn't even think to; changing a bum is something I don't think about, and just another thing to do like taking a dirty cup out to the kitchen or something.
I'm sorry if that makes me ill mannered, but it certainly wouldn't, and never has, bothered me when friends have changed their babes round my house. The only thing I find odd, and only because it tickles me cos I'm silly, is when babes are being potty trained and you are outside (like a park or somewhere) and the poor ****** hsa to sit on the pot in front of everyone!
However, I don't think it was very kind of her to mention about you having to get used to it, I find that tantamount to "You wouldn't understand as you haven't got your own kids", and is patronising and downright rude.