One book I have says the meaning is unknown, but it could either be from "mann" meaning "circuit, round, promenade" or from the name Manan (Manana) meaning "lichen."
A website I found says Manana means "semolina," and is used in the form Maneh as a girls' name.
The other book I have says Mane means "fern."
There was a 4th century Armenian virgin hermit saint named Mane.
The first book is usually the most trustworthy of the two I have. The website I found http://armenian.name/index.php?a=index&d=2
seems pretty good, though! I'm no expert in Armenian names, but I have studied them a bit.