I'm not a mom, but I take my nieces (5 & 7) w/shopping w/me @ times. When I take my 2 1/2-yr-old nephew, I only get weird looks if he's behaving completely awful, which luckily only happened for 15 seconds.
I don't have a problem w/women who shop w/their children, but I've seen babies who need to be nursed, get completely ignored by a mom who continues to shop. It doesn't take much to put something on hold, step outside to feed the baby, then come back. It pains me to see a baby/child have his/her mommy forget about feeding or changing cries.
