Since all we know is that she cannot sit up on her own, everything else is just hypothetical. But for a child who cannot sit up, I wonder if she can get into and out of the raft on her own. Getting in is one thing, if they will allow assistance. But getting out is tricky business even for fully able-bodied people. My son was able to pop right out, but I (a normal sized person) struggled to get up before the next raft came down! If you will have to get her out as well as yourself, this might be a place where you will want to watch the exit for a bit before making the choice to go on the ride.