Hi, I'm not an instructor, but I think it would be a mistake to get an F131. The Futura is a freerace board, it is not designed for people still learning to plane and waterstart.
You might have to bit the bullet on this one and buy a SB Go 131/141. You will struggle to get your 9.5m on the Go 131, but the Go141 will be good with the 9.5m.
Realistically, you need the F131 and your wife needs either a Go 121 or 131 depending on her level. I don't think you will be able to find one board that will double up as a learner and high performance board.
The Go is the same shape as the carve, so a Go 121 would last your wife for a while