What does Wren mean?
A nature name taken directly from the English word for the small, energetic songbird, from Old English 'wrenna'. It also exists as an English surname. Its use as a first name is modern.
What does Navy mean?
A modern word-name from English 'navy' (a nation's fleet, and the deep blue color named after naval uniforms), ultimately from Latin 'navis', ship. It has no older history as a personal name; its appeal is the color and the nautical association.