Ooh la la, Lúthien...

[Lalaith]

Idril managed even to get Daddy's blessing for her mortal beau without all those ridiculous shenanigans

well, yes, because it suited Tolkien's plotlines for Gondolin/Tuor better. I don't think it was due to any intrinsic difference between the characters...
Plus...wasn't Idril an even earlier character in the mythology than even Luthien? (I may be wrong on this)

We'll just have to agree to differ on this one Mith.

Rune's idea about feminism is quite interesting.

women have done great deeds, but that does not make you a feminist

As is Mith's point about Priscilla.
Eowyn (written I think to please Priscilla - where did I read that?) was aware of the constraints facing women and rebelled against them. Neither she, nor probably her creator, had ever heard of the concept of feminism. Does that make her, nonetheless, a feminist figure? I think so. Rune, and others, may not.

Which reminds me.
"I may have the body of a weak and feeble woman; but I have the stomach of a concrete elephant. First I'm going to have a little drinkie, and then I'm going to execute the whole bally lot of you."