When Sylvia Plath died, her executor was her ex-husband’s sister. This sister was, effectively, given full authority to determine Ms. Plath’s writing legacy. Ms. Plath likely listed her as her executor at a time when she was still married; we may never know if she wanted her to remain as her executor, or if she simply forgot that it was set up this way, and we will never know if her literary estate was managed in the way that Ms. Plath wanted.
Artists have unique considerations when it comes to estate planning. There is not simply money; there are also copyright and trademarks, and the ability to licence or sell artworks for years or decades to come. It is particularly important to choose not only the executor of your financial estate, but who will manage your artistic legacy.