Gil Kane (born Eli Katz 1926-2000) worked in comics from age 16 in 1942 and was one of the most prolific and influential artists of his era. He is best known for co-creating the Silver Age Green Lantern (I still think of him as the Green Lantern guy) and Atom as well as for, with Gary Conway, killing Gwen Stacy and blaming it on the Green Goblin.
He was considered quite an intellectual in the comic field who often said that comic artists as a group were intellectually superior to the writers, a widespread idea at the time that helped spread the Marvel practice of giving artists heavy responsibility in creating the stories. The main result of which was a bunch of badly-plotted comics that were fun to draw.
I've never examined an original Gil Kane at leisure before and am struck at how much this page, which looks striking at long and middle distance deteriorates on close examination. Possibly, Kane knew how much work he needed to do to make a page that looked fine when reduced to comic page size.
This an adaptation of Wagner'sRing of the Nibelung (I freely switch between alternative spellings of names, etc. here and don't have umlauts), specifically volume 4, The Twilight of the Gods better known as Gottergammerung. This cycle is over 8 hours long and includes 4 operas. The action here is in act 1, so the comic must be something like 80 pages long.
The pretty and svelte lady is the Valkyrie Brunhilde, best known (no joke) as the inspiration for the expression "It's not over until the fat lady sings". She isusually shown as being fat and wearing armor with a horned or winged helmet. Actually, the character isn't fat, it's just that virtually every opera singer is fat, leading to confusion for opera goers who take the expression seriously. She is telling fellow Valkyrie Waltraute she won't give up the ring because she loves Siegfried.
Alternatively, she won't give it up because only Hobbits ever give up or offer to give up the precious (note she actually uses the term) and she isn't a Hobbit (note the hairless feet).
Alternatively, per the Green Lantern connection, she won't give it up because she wants to do cool things like make giant green hammers with it.