As a fellow "little sister" I can fully understand the patience it took to wait for your turn with the bike. It is funny how the "bigs" in the family can be inspirational without even trying.
My sister and I got similar bikes at the same time for Christmas when I was three. One of the few times I did not have to wait for my turn. She took to hers the first day with the classic push from dad. It would take until I was five and so determined that I spent hours in the driveway teaching myself and falling into the big thorny rose bush. I was thinking of my big sister's success the whole time!

So sorry to hear of your loss.
But it is uplifting to see how you are cherishing your time together.
I hope you get to celebrate her life on a shiny new red bike soon.
Don't forget the pictures.