We must forget that God can change the heart of anyone. Nothing can resist the Will of God. I remember reading St. Catherine of Siena wanted Christ to send Graces of Reconciliation to a person with a hardened heart; but Christ refused her request on the basis of Divine Justice. St. Catherine then asked for help from the Blessed Mother. The Blessed Mother made the same request to her Son Jesus Christ but on the basis of Divine Mercy. Christ immediately granted the same request and the person with a hardened heart was saved.
As the mother of your daughter, you have great spiritual authority in all matters worthy concerning your child. Two mothers, the Blessed Mother and any mother, conspiring towards saving their child, surely will be successful.
The principal ways the devil works oppression on any one is through corporeal facilities such as memory and imagination. For example if one is experiencing nightmares compose a prayer like this:
PRAYER AGAINST NIGHTMARES.
Dear Jesus I ask that you hold my imagination for me while I sleep.
Keep it with you where it is safe and protected so that I may sleep
well this night and in the morning give Praise to You because I am well rested.
Amen
Hope this helps.
