The trouble is that she, like so many others, thinks of sex as dirty. She doesn't want her children to even think about sex until they are 25 years old, presumably because that would somehow debase or ruin them. There is nothing wrong with sex and sexuality. There is nothing wrong with desire. Wishing to keep that entire portion of the human experience away from one's children is a sad thing indeed as it displays an an acceptance of internalized shame surrounding a normal part of life. Sexual activity has its own troubles, pitfalls, and challenges of course, as does everything we do, but glorifying virginity and celibacy helps nothing and causes plenty of harm.
I think the extremes to which our society views clothes as some kind of magical armour are ridiculous - for example, on the subway people stand close together without issue but if their clothes were removed they would all suddenly be guilty of serious crimes. What is it about a couple of layers of porous cotton fibres that differentiates a bored commuter from a dangerous sex offender? What amazing powers textiles have!
Of course I am not telling you that you need to be naked - you should wear whatever you bloody well please. What I am saying is that if a person walks around without a protective layer of clothing covering their genitals the appropriate response is *not* to put them in a concrete box but rather to just shrug and continue on with your day. If they were going to hurt you a pair of boxer briefs would not protect you and the suggestion that it is tantamount to assault to merely exist as you are in the presence of others is absurd. It is much like the way I support freedom of religion despite being an ardent atheist - if you would not want others imprisoning you for dressing the way you like you should not support imprisoning them for dressing the way they like as someday the balance of power is going to shift against you.
Sex and sexual desire are not wrong or dirty. Even if they were nudity is not sex and being naked is not an assault on everyone around you. Our laws should reflect that, as every time the government uses force to imprison people for victimless crimes we erode our freedoms and waste precious resources only to wreck people's lives. It isn't as though removing laws against nudity would suddenly result in hordes of naked people running through the streets - Toronto made women going topless legal years ago and I have not yet seen a single woman behave differently based on that change. A few people would go about naked, get gawked at, and then everyone would realize that nothing has changed and they would all get back to doing their own thing. A change in these laws and norms would likely have minimal measureable impact on behaviour but it is still the right thing to do.