You are right, Menke, about the three possible meanings of "-lind". But etymologically they are all one: The tree (German "Linde" is so called, because its wood is flexible and thus very useful for making bows. The same applies to the snake (as in German "Lindwurm" = dragon), not the part about bows, but its ability to bend. This is at least what my etymological dictionaries say (Kluge and dtv).
I don't know about the name Ashlyn(n), but I guess, the ending -lin can also be a deminutive.
Keep going, Menke, you are a thorough worker and make good contributions to the board, as far as I can judge.