It's a tight squeeze ... My DBF and I fit on our last trip but it was a lot more comfortable when we went separately. The opening of the ship isn't very wide so I had a difficult time getting in after my DBF was already in.
I'd say you could fit, but it would be best not to. I would go for 2 rockets. One pooh and a small child would be about max. As a note, this ride is difficult for me to get in and out of, but once in by myself I'm OK.