Tomorrow, on the 23rd April 2017, my younger sister is running the London Marathon.
About 8 months ago, she had never been on a run.
Tomorrow, she will run 26.2 miles as a part of Team NSPCC, and I could not be more proud if I tried.
Anyone who knows my sister will know she is stubborn, determined, fiercely independent and highly ambitious.
If she puts her mind to something, she will do it, even if she has to alter the plans a little along the way.
Interviewed yesterday on BBC Radio Newcastle, Kitty recalled watching the London Marathon on TV with our dad last year, saying she couldn't think of anything she would want to do less than go and run a marathon.
Two months later, she was a member of Team NSPCC.
Eight months of training later, the day is almost here.
Kate being Kate, taking on the challenge of going from non-runner to marathon runner was not enough, so she decided to combine it with a complete lifestyle change, adopting a plant-based diet, and removing gluten and refined sugars.
When she first told us of these plans, I have to admit we thought it was a passing idea.
But then the months went on and the training miles mounted.
She started a blog tracking her training and the reasons she was running, she had a new daily routine, her fitness levels were on the up and her new way of eating became not just a fad, but a new way of life she had fallen in love with.
Over the last eight months, she's transformed into someone who loves running, who learns about food and uses it to fuel her body.
She's done all the training alongside her usual hectic schedule whilst at university in Durham, and hasn't let her eyes drift from the end goal.
That goal is nearly here.
Tomorrow, she will run 26.2 miles.
Kitty's determination and independence always impresses me, but this year has undoubtedly seen some of her biggest changes and challenges yet, and I'm not sure anyone around her could fail to be inspired by the changes she's made and commitment she's shown.
Whatever her time tomorrow, whether she sprints or crawls over that finish line, she's left all of us in awe, and we are so, so proud.
If you'd like to help her along the way and support the incredible work of the NSPCC, her JustGiving page is right here.