You can look at it two ways. You can be with her for caring, support, love or whatever that everyone else has failed to be. Or you can be with her for the sake of doing extra kinky shit that a normal person wouldn't do because what difference does it make if she's going to die soon anyways? Both lead to yes.
And yes the 2nd half of that is facetious - it's up to you and what you feel is best to do. If she expects whoever stays with her to be a slave for her until the end, that's not really fair to you, but if it's just to have some caring/compassionate mate while she's in her waning moments, then why not do it?