Ruling on women curling their hair

Some female students with fine hair try to make it thicker in the ways that are known to girls. What is the ruling on that, knowing that this is one of the things that westerners do?

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

The scholars say: there is nothing wrong with curling the hair. If a woman curls her hair in a manner that does not imitate the way that immoral kaafir women curl their hair, there is nothing wrong with that.