All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The parents’ maternal uncles are considered maternal uncles of their children and grandchildren as well. Consequently, they are Mahrams to those daughters.
Allaah Knows best.