Here's a Prayer to St. Monica for mothers to pray for their children:
Dear Saint Monica, patron of all mothers,
please take my children under your protection,
especially those who have turned away
from the path of Christ and his Church.
Help them be faithful to the grace
of their Baptism and Confirmation
and bring them home to the Altar of the Eucharist.
Despite the temptations and difficulties
that face them,
help them find the wisdom and strength
to walk always with the Lord.
Dear St. Monica, pray for my children
that they may share with you and all the saints
the peace and joy of life forever with Christ.
Amen.