Of course! That would be the most obvious choice of plots for the 5th book in the series (after Midnight Sun, of course.) There was a really good fanfic on here called First Light-Renesmee and Jacob's story. It was amazing- it told the whole story of Renesmee (once she is all grown up) and Jake. It reads like the 5th book would. It was hands down my fave fanfic on Twifans!!!