Have to say I love your daughter's name Juniper, its beautiful! From your list I like Hermione, Matilda, Lyra and Iris. Arthur William sounds like a good solid name. If u like Cassandra how about Cassie?
Hi , really unhelpful but I love all you girls names , Juno is top of my list at the moment and your others ideas are beautifully unusual/ individual. The boys names are great too, only Arthur Wiliam seems more traditional than you other choices. So exciting for you!!