lea (lee, lay) noun

A grassland.

[From Old English leah (meadow). Ultimately from Indo-European root leuk-
(light) that has resulted in other words such as lunar, lunatic, light,
lightning, lucid, illuminate, illustrate, translucent, lux, and lynx.]

Hmm--all the ref.'s relating to light...did lea come about because a grassland is open? Nothing to make shadows, or to hide behind?

and the lee of the stone?

The Shadewell Shenanigans or The Coldstone Conflict?

My Etymological Dictionary of the English Language doesn't directly address the connection with light, but what it does say supports your theory:

LEA ... lea is cognate with prov. G loh, a morass, bog, wood, forest ... ... L. lucus, a grove, glade, open space in a wood (?) ...

Thanks--good to see you! [blowing kiss e]