There's no evidence neither from the book of Allah nor from the Sunnah of the Messenger Sallallahualaihi wasallam obliges women to cover their faces.
Whether they bring a general Aya or Hadeeth or they twist the language to help them.
The Majority of scholars inclduing the 4 Imams didn't say it's a must yet we have some over zealous people who want to enforce it.
On the other side, there are immence evidences that covering the face is not Wajib.
Of them Hadeeth Aisha in Al bukhari and Muslim when the aya of Hijab was revealed and the women of Ansar covered their heads so no one could identify (know) them due to darkness. This means if it was not dark then it's possible to know them. If they covered their faces then whether it's dark or not there's no use of this statement because they won't be known anyway!
If you believe it's a must then fine go ahead and cover it, if you don't then it's also permissible.