Mark Chapter 16 (finally...)

9 Now when He rose early on the first day of the week, He appeared first to Mary Magdalene, out of whom He had cast seven demons.

Why does Jesus first appear to Mary Magdalene? Why didn't he first appear to Peter, or to the other disciples?
Well, we can only guess and make suggestions about this. We might never know the perfect answer (as long as we are still on earth)...
So let's make some suggestions:

1. After Jesus has healed her from the demons, she gave her life as a sacrifice to Jesus.(Luke8,2. And as we know, that "each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death."(James1:14+15) (see also Lumi's sharing on Mark Chapter 5). So I think that it was not easy for her to change her life totally and to come from the wrong to the right path. She had to give everything up, which she has had before and followed Jesus))---------The disciples did this as well
   
2. When Jesus was crucified, she was present and stood by the cross(John19:25)---------- Some of the disciples did this as well (like John (John19:26)) and others have tried to follow Jesus (like Peter).
3. After Jesus was dead and all hope for the new kingdom he promised was gone, Mary Magdalene cared about his corpse and bought spices to anoint him. ------- Whereas it seems, that the other disciples did not care and lost hope in him... ->they continue to fish (John21:2+3) although Jesus has already appeared to them twice (John21:14).

So I think that the last point might be the reason.
What else would be interesting: What did Mary Magdalene thought in her heart?
The answer to this question is perhaps the reason for Jesus appearing to her first. But as we don't know her thoughts we cannot answer the first question with a perfect answer, only with suggestions.