[Lush]

Ah, Sir Squatter, you must have picked up on the fact that one silly wench always looks for another silly wench to indetify with (are you sure I wasn't having lunch with YOU the other day?). I was actually overjoyed when I found Aredhel in the Sil, if only because most other females that populate ME are so darn perfect. And if they're not, they still come to good in the end. Not Aredhel.
By saying this, I'm not trying to celebrate stupidity and selfishness. I am trying to point out that Aredhel, in my eyes at least, makes Tolkien's work more complete. Here is a woman who doesn't know what she wants, and she reminds me of my, er, "friend..." You know, the girl who says, "I want an Italian boyfriend! I want a piece of candy as big as my head! I want to go shopping at a Morroccan bazaar!" while having no clue as to actually what or who will please her, or how she can please others. Self-destructive behaviour is even more amplified in the case of the "White Lady", because Aredhel isn't just jabbing a poisoned needle into her own vein, she effectively poisons her city, albeit unintentionally.
I think that perhaps you are right, and that Aredhel's story is in part a jab at loveless marriage, and an example of the brilliance of Morgoth (as in, the Oath). Or perhaps a criticism of over-indulgence and moral weakness. Either way, I find it enjoyable to read, for whatever twisted, or ordinary reason.