On the flip side, I had my MIL & SIL go on and on about how it's so natural to give birth and women do it all the time ect, ect. and the day my first child was born they came to visit saying "see, it's not that bad is it??" and I nearly burst into tears as I was traumatised by it! Time most definatley must muddle the brain as to how painful it is (was) - either that or I'm a wuss. I had no drugs/pain relief with either of my births, but I can totally understand why people would be scared and want c/s's to be honest. Also, a friend of mine has had both type of births and had more medical complications after her VBAC, including severe incontinence (bladder and bowel). So, each to their own with regard to choice and just becaue someone chooses/wants a c/s doesn't necessarily mean they are uninformed. I'm glad you didn't say anything to the ladies you overheard, but your mum/sis did sound a little patrionising towards you.
Good luck to you and I think, with your attitude, you will have a terrific birthing experience.