Personally, I don't really have much issue with the character, it's not like we're going to be fighting against them, and there's superheroes who are more overpowered, certainly. There's reasonable enough weakness that the character has, after all she seems relatively easy to bind/incapacitate, which I would say makes up for the fact that they can't die.

The only sort of way I could see the character 'dying' was if they could be forced out of the physical realm for a period of time, more of a temporary death.

That's just my two cents on it though, up to Intel at the end of the day.