Sadly, not even the school uniforms Elly loves because she isn't aware of the schoolgirl fetish can protect her children from the petty snobbery that makes peer pressure a blight on childhood. Always and ever, a child is going to feel the pressure to belong and there's very little parents can do about it. I also know another sad thing: when Elly read about King Canute and his stating that despite being ordained by God to rule England, not even HE could command the tide, she took it to mean something other than what it did. Instead of being a reminder that Man's power is as nothing compared to God's power, she took it to mean that he just didn't try hard enough.
Always and ever, Elly fought valiantly to do the impossible for a very questionable reason: the fear that THEY would judge HER for how her children dressed. Given that we're probably talking about the same THEY who would make sure that television and movies always told the exact truth and given that Lizzie's feelings had to be sacrificed on the pagan altar of Elly's non-existent status in the community, it's not that she really wanted to keep Lizzie safe so much as it was that she didn't want to be publicly CALLED negligent. After all, it's one thing to forget your kids exist when you ain't looking at them but another to be called a stupid woman who thinks that things cease to exist when you can't see them. It's a third, worse thing to act like a complete jerk to your kids because you think that since the same hassles you went through no longer occur simply because you no longer have to deal with them, any reminder that they do is an evil LIE that you simply cannot abide.