I posted to this on the opinions board but you're absolutely right, it's one of those goofball sites with made-up names and imaginary meanings...again...can't someone run them out of town? LOL
Part of what I wrote over there (okay, I'll admit, I'm recovering from surgery and have to go for a 'corrective procedure' next week so mildly grumpy ;o) :
1) Avalyn was never an Old English personal name or word
2) it would be Afalyn anyway as there was no V in the language
3) the closest you find in OE is the word Afiellan which means 'to fell (a tree); kill; subvert, abolish; overthrow; offend' which doesn't exactly appeal
4) 'beautiful' was 'hiwe', 'life' was 'saul', 'breathe' was 'ethian' - if you can get 'Avalyn' out of those you're better than any other Anglo-Saxon scholar in the world.
If it were attempted out of Old English it would be made up of the elements afol + lynd, Afollynd-Afollyn-Afolyn-Avolyn-Avalyn) which would mean 'mighty fat'....you can see why no one ever bothered with this one when they actually knew what it meant.
There is a Norman name Aveline, Old French diminutive of the Germanic Avila, from Avis derived from Aveza, short form of many Germanic compound names containing the mysterious element av-. The most likely meaning contender is 'struggle' but German scholars continue to look for more clues. But for the time being 'little struggle' is as close as it gets though that's never pointed out by anyone in the business of selling names even if they know it. Since the Middle Ages, the shared form of GermanAvis with the Latin Avis 'bird' has meant that many bestowed the name with that mistaken Latin meaning in mind. But for the bird meaning I much prefer the Welsh Aderyn.
How about a fictional placename using English elements - Alflyn would mean 'fairy pool' which is *much* nicer. And there are great Anglo-Saxon dictionaries out there and it makes a fascinating study - orc really meant 'demon', ent really meant 'giant', great for Tolkienites!
And of course, there's Avalon, associated with the Welsh afellenau 'apple trees' and in myth one of the 'Isles of the Blest' which is quite nice, even with the pseudo-Welsh spelling Avellen (Welsh f sounds like English v). I'd much prefer a name of substance and real history to some made up form with a made-up meaning."
And I agree with you 100%, it looks like one of the many modern meldings of Eva and Ava - Evelyn to Avalyn seems pretty much a no-brainer to me when put into that context ;o)