In her report she tells us what it was like taking part.
"I was so excited and nervous at the start of my first marathon.
My number was 30 and I was at the back.
The hardest part was when I was on my own all of the way.
The group in front was too far ahead to see.
I was not sure where to go since it was my first race.
I got lost so a policeman directed me.
Cheering crowd
The crowds cheered me on which made me push harder.
My grandparents were cheering me and I saw my friend Sarah.
Final push
When I saw the finish line I pushed as hard as I could and saw my dad and sister holding a banner saying GO REBECCA GO!!
When I finished I was exhausted and a lady handed me a bottle of water.
I was given a medal and Michelle (my coach) told me I came second in my age group. I was very happy!
We waited at the finish and saw Paula Radcliffe, Tanni Grey-Thompson and Paul my coach.
Then we all went home - tired but happy!"
Rebecca, 11, London
Why don't you write us a Press Pack report - and get it published on the site?!
It can be about anything that's happened in your local area - or your views on the news.
Watch Laura's report
I'm competing in my first marathon
