Trying to fill in someone else's shoes is futile. The person will at best be a shadow of the one who shoes they are trying to fill. It is best to have new shoes (their own) rather than live in the shadow of another
I'm by no means a runner - I have avoided it like the plague in most cases. But occasionally I feel like running just because I can. There will come a day when this body just can't do the things it used to. Live life while you are able to.