Huh? That's like saying "My mother is now my citizen-sister, since her relationship to me now is not mother/son but taxpayer/taxpayer."
Ridiculous. One's mother is one's mother, period. Motherhood is not something that can be switched off; it exists eternally. The Blessed Virgin is Jesus' mother, then, now, and always.
By the way: Jesus did not become our Lady's Savior upon His resurrection, as you imply. He always was her Savior, from the moment when she was conceived: "And Mary said: My soul doth magnify the Lord. And my spirit hath rejoiced in God my Saviour." [--St. Luke 1:46-47]. Jesus wasn't even born when she said those words, thus demonstrating that Jesus had already saved His mother from eternal damnation.
You are free to believe that, however, I don't see scripture supporting any kind of parent/child relationships in heaven except between us and God.