Brain Teaser for the week: Answer correctly and get a prize

Here's the brain teaser for the day, you can take your time to think this through, remember we give rewards to two correct answers at the end of every week.

 Brain Teaser
Two days ago Mary was 7 years old. Next year she she will turn 10.
How is this possible?

You can post  your answer as a comment, all answers must come in before 11:59am on wednesday. Winners would be contacted.