OP, your baby, your choice, of course. But - and this is a general point, not directed at you - I have honestly never understood why people in search of an unusual name go for names of a different kind of thing, rather than choosing an unusual human name.
As others have said, River means a river, Raven means a big black bird, Luna means the moon etc. To me, it seems odd to use them as first names for a child. Using the name of a particular river or bird seems much more understandable, because, for centuries, individual rivers, birds etc have been linked to myths and legends and/or treated as supernatural creatures. For example, Sabrina was the goodess of the River Severn; Afton is occasionally used as a girl's name in Scotland, because of a famous poem in which it is called 'sweet Afton'. And of course flower names are well-loved, because they symbolise beauty.
Please excuse me rambling on....
I really like Violet and Tabitha. Verity is a nice name, too, with an inspiring meaning.