Like PriaposLovs, I, too, have an "ex-post" etymology for you!
That name you dreamed up, "Leahnya" may be a combination of the names "Leah" and "Nya" -- with a subliminal meaning...
"Leah" means "weary" in Hebrew. "Nya" is a name which has been discussed at least a couple of times in the past here on this message board -- it being the name of the leading female character in the movie *Mission: Impossible 2*.
I believe you may have been watching *Mission: Impossible 2* late one evening, and you were so WEARY that you drifted off to sleep. Or maybe watching it just *made* you want to drift off to sleep. Whatever the case, one night your WERE sleeping, and that name "Nya" somehow crept into your dreams.
So, "Leahnya" is a subliminal result of your being bored to sleep by *Mission: Impossible 2* (which wasn't really a bad movie -- it just, like the first movie, had nothing on the original teevee series).
Of course, if you've never seen *Mission: Impossible 2* or ever even heard before that the name "Leah" means "weary", then that just blows my whole theory.
But that's okay, coz I liked PriaposLovs' better, anyhow. :)