I think her going “missing in action” would be your best option. For example, something happens and everyone assumes she’s dead, but one of the characters holds out hope that she’s still alive. This will sow doubt in the reader that she really is dead and when she’s proved to be still alive it’s pay off rather than a cop out. Does that make sense?
I use this tactic in my war novel. The MC receives a letter saying that her brother is missing in action, presumed dead as his plane has failed to return from its mission. While everyone accepts this and advises MC to move on as he is almost certainly dead, she refuses to believe this. In actual fact, he’s been taken prisoner by the Turkish and later escapes and returns to her. Since the point of view character doesn’t believe he is dead, we don’t want to believe he’s dead either and when he turns up at her doorstep we are happy instead of skeptical or annoyed.
Mahalo keia huiʻana