Here is what we know -
1. She was from Magdala in Galilee
2. Jesus cast seven demons out of her.
3. She joined the band of disciples and followed Jesus where ever he went. Luke 8:2
4. She was at the cross when all the male disciples had fled (Mk 15:40, Jn 19:25)
5. She observed Jesus burial (Mk 15:47)
6. She came with the other women to the tomb (Matt 28:1, Mark 16:1, Luke 24:10
7. She was the first to discover the resurrection, and first to report it to the disciples, and first to see the resurrected Christ as she lingers by the tomb, after all the others have gone.
(John 20:1,2, 11-18)