I don't really like it too much, it sounds a bit garbelled to me what with the mawr sound at the beginning. Like morena actually which sadly means dark-haired in Spanish but I think it sounds pretty. Out of those I like
Morwenna Lake just because
Lake is such an interesting mn.
Morwenna Hope works well I suppose though I dislike the name
Hope.
Juliet is too much for the name it needs something very short and simple,
Briar (and yes I prefer Brier too) is also just a bit too long or a bit off. I think the name really needs just one syllable.