Women have the free will to do and wear what they please (after they have been advised by learned religious men). Once they have told the requirement of dress for a Muslima, leave them to make their own choice.
If they choose modesty say Alhamdulilah but if they don't dress modestly then make dua for them and warn them of the spiritual consequences. Don't force the women though and threaten them with violence, that is not moderation and Islam is a moderate religion.
The Prophet Muhammad (peace be upon him) said: "Do good deeds properly, sincerely and moderately. . .Always adopt a middle, moderate, regular course, whereby you will reach your target (of paradise)." - Sahih Al-Bukhari, Volume 8, Hadith 470