Straight off the BA FPP site:
Kathryn B777 SFO: "I joined British Airways seven years ago from Ryanair where I flew the B737-200 for three years based in Dublin. I came to British Airways with just over 2500 flying hours so was sent directly to longhaul and the B777 fleet. Not only was I very excited about the prospect of longhaul flying but it also gave me the opportunity to fly with my father who is a British Airways Captain on the B777 fleet.
Is it normal to be sent straight to longhaul after 2500 hours on B737?