The Deceased in a Dream

Your Eminence! After the afternoon prayer on the Day of 'Arafah, while I was fasting, I was woken up in my dream by someone saying: A woman wants to see you. So I woke up to this alarm, and it was my deceased mother coming. I greeted her and embraced her to my chest, and she said to me: May Allah reward you with good. Then I woke up from my sleep, and my son was a pilgrim, so I informed my family of this, and they said: If Allah wills, it is good. And after my son returned from Hajj, I told him about it.So he said: I remember my grandmother in every situation and I make du'a' for her. Please advise us, may Allah reward you?
It appears that this is good, if Allah wills, and it indicates that your mother knew about the du'a' you send to her, so she thanked you for this.