While some people only travel on one cruise line, personally I would find that very boring. Variety is the spice of life, so we like to try as many different cruise lines (11 so far), ships, and ports as possible. Just because she is the Godmother and gets free cruises for life, perhaps she's one that feels the same way. We've been on Oceania and I could never imagine only sailing on them - it would drive me crazy even if it was free. So if she wants to go on other cruise lines, good for her.