It's nice she had a kid and all, but I don't know if F4 is ready for Franklin just yet.
Maybe if they get to the fourth film (doubtful, but we'll see). Until then, I'd like to see one more adventure with the 4 doing their thing.
The moments of them working as a team in the last movie were just great. I want more.
Just remember what happened to other film series when a sequel introduced a young child. Ick.