The nun was taking the quoted passage out of context. And today most people do that. Here's a VERY brief rundown on the context of Leviticus and Deuteronomy:

There are three types of clearly defined laws that God gives in Scripture:
1. Moral Law: These are laws that apply to everyone for all time. "Do not murder" is an example.
2. Civil Law: These are the laws given by God to the nation of Israel at the time of the Exodus and while they were their own nation. These laws have the purpose of establishing order and to mark Israel as different from the practices of neighboring countries. "An eye for an eye" (Exodus 21:24) is an example. What the verse is saying in context is ONLY an for an eye; nothing more. God is stressing balanced punishment to fit the crime in Israel and not the harsh and brutal penalties enforced by the other nations at the time. (And not an actual eye; balance is the point here.) CIVIL LAWS were ONLY for the nation of Israel at that time. Some make sense even today, others not so much. None are required.
3. Ceremonial Law: These are laws and practices prescribed by God for worship and a religious life. They were intended ONLY for the Israelites and any outsiders (Gentiles) who converted to the faith. These laws ended - by God's will - when Jesus died on the cross, having perfectly fulfilled all the laws. 

The verse the nun quoted was a Civil Law and does not apply today.
The verse Marta quoted - Galatians 3:28 - is also taken out of context. Paul was referring to the saved status of Christians through faith in Jesus as Savior. He was saying that when it came to salvation, all people are equal.

In fact, there are no restrictions for dress in Scripture, now that the Civil/Ceremonial Laws of the nation of Israel are concluded. There is encouragement to not cause offense in your daily dress, manners, and behaviors. And of course we should honor and respect those God has put in authority over us for our good.

Sorry for the lecture. I hope some of you found it interesting, though.