TLDR
- Too long for comment...
- If Odin can die...
- That said, we don't know her current status for sure...
- We also don't know what Asgard is...
So obviously, Asgardians can die. They have done it all throughout time. Odin's father and grandfather died, Friga died, Odin died... I have a hard time thinking that if they can die that Hela can't for some reason... I suspect that that if no other Asgard has been truly immortal up until this point that Hela is not as well.
That said, it is possible that she has discovered something that no other Asgardian has before. This I think leads to what your real question is: What is her current status?
When the "royal" family is imbued with abilities they become more than just a typical Asgardian. Thor, as we now know, has the power of thunder within him and does not need to call it from the sky or his hammer. Hes gots sparkles...
Hela is the God of death, Odin's executioner and really, really good at killing people. However, we don't know what her "innate" ability was. Perhaps in being the God of Death she has some strange ability that allows her to fully cheat death; similar to how the God of Thunder has control over lightning. And maybe that is why Odin couldn't kill her. My first assumption was that it was because he didn't want to kill his daughter and wanted to put her in timeout for a few millennia, but maybe it was that he actually couldn't do it.
Toward the end of the movie we see the people of Asgard escape and after we see that "those foundations are gone" Asgard appears to be completely obliterated. It was my assumption that she would have been destroyed then, even if she had leapt from the path of Surtur's blade when it came down or survived the blow somehow.
Again however, she draws her power from Asgard. But everybody constantly says that "Asgard is not a place, it is a people." So what Asgard does she draw her power from? Is it the place or the people? If Asgard is truly a people then what Hela draws her power from still exists... is that enough to have saved her?