to-veil:

Modesty is a virtue that, like any virtue, takes time to fully learn, understand, and incorporate into ones life – especially if modesty is not something someone has actively tried to embody before.

This is why shaming or belitting those who are not modest in dress or action is ineffective. Normally the person feels vulnerable and embarressed, as if an intimate part of them was dangled out to the world just to harm them over it.

Instead, think of ways to be encouraging. “I see you at Mass a lot, so I figured a great birthday gift would be a maxi dress/dress shirt to wear when you are able to make it!” “The AC can be terrible in the chapel, so I always wear a cotton shirt over my tank top to breathe better. If you want, I can lend you one whenever we hit up Adoration again.” “Say, I have some left over lace fabric from my last crafting project. Would you say no to a simple hand made veil as a Christmas present?” etc etc.

You never know if someone is unable to buy affordable clothes, is unsure of how to dress modestly, is dressing a certain way because of nerve issues, etc. It’s best to simply be supportive and positive, listen to their feedback, and offer help however you can.