It’s now a Remembrance Page, so no one is in control of it once this is done UNLESS she chose a “legacy contact” before her death. (You can do this in settings, you can also choose for your account to be deleted after your death if you so wish)
==But== even if she chose a legacy contact, they are very limited in what they can and can’t do, and they cannot remove content.
From Facebook’s help section:
Can I add or remove a piece of content from a memorialized Facebook account?
Once an account is memorialized, content can't be removed from it. If the person added a legacy contact to their account, the legacy contact can do things like:
- Change the person's profile picture and cover photo.
- Write a pinned post on the timeline.
- Respond to new friend requests.
If you feel that a piece of content on a memorialized timeline doesn't follow the Facebook Community Standards, you can report it with the
Report link located next to that piece of content.