I mean... I'd be a baby, so like... logically let's look at this. I'm in my late thirties, and presumably my best friend would be around the same age. In this scenario, I am now a baby.
I'm not going to be able to walk or talk effectively for at least five years, and nobody is going to take my words seriously or let me go anywhere alone until I'm... to lowball things considerably, let's say thirteen. I am now a little teen... and the person who murdered me is now like... fifty? They might have kids, they could even have grandkids at that point, and I meanwhile have an entirely new life and the chance to do what many people would love to do; start my life over with all the knowledge and wisdom accumulated through adulthood.
You know the phrase, "the best revenge is living well"? Well, that's where I'd be at here. Unless the person who murdered me has become evil queen of the land or something, why do I care when my life is clearly way better than theirs? I'm a freakin' fresh-faced teenager with the life experience and knowledge of a professional artist with two degrees. All the skill and none of the wrist pain! 
I mean, if the police investigation into the murder had stalled and I had the ability to point them at key information, I'd obviously do that.... But why risk my awesome new life where I'm a teen art prodigy just to get back at somebody? It seems pointless. Yeah, enjoy your arthritis, murderer, I'm over here shopping for cute miniskirts.
...It probably wouldn't make for a compelling story. 