Christians (and Jews) have to be churched / mikvah-ed (ritually purified) before they can enter society after childbirth again. This is to purify the pollution of childbirth. Muslims have to wash after sex (dunking essential) as bodily fluids are unclean.
Ancient Greeks thought of as women as miasmic or polluters. They were banned form many temples / games etc. and it was polluting to even meet a woman if a man was off to pray/ play. So women's lives were heavily proscribed even then.
There are many cultures who think of menstruation / bodily fluids / semen as filthy pollution.
Ritual washing is very common, to purify before prayer, and ritual atonement such as confessions and penance are very common in many cultures.
The boundaries between profane and sacred is delineated by these rituals.
Religion has a lot to answer for, hasn't it!
Bless the looney lady though, she's absolutely right about the pain of childbirth being Eve's payment for her sin, as it is in the bible.
My feeling is, if you are a Christian, you can't just pick and chose your bestie religious bits á la carte. IMVHO, all religions are a set menu, with a set price. which is why I don't believe in any of that guff
OP, I think you probably 'encouraged' her!! Talking to strangers is asking for trouble 
especially those religious types.
Oh and best of luck with the birth of your little babe. (Don't forget to ask to see, and have the screen taken down a bit for the actual delivery, if that's your thing).