I like the Lady O, but I'm thinking it will get shortened to Lady and Lady is a bit doggish, probs just me thinking of Lady and the Tramp (picturing the two doggies kissing with the spaghetti, you know!). Stella sounds a bit more cattish to me. Or if you wanted to go with the O, how about Ophelia. There was a painting I used to like called this I think it was based on a story, my memory is really bad, but it was pretty but had hidden bits within the bushes, I think like hidden depths. Does this make sense? Gonna have to google it now