When it comes to caring for loved ones and making tough decisions, there is no "perfect" way to make decisions. A family meeting is often a good way to discuss all of the concerns of the family and make a plan to support one another through this difficult time. It will also help clarify what the loved one needs and which family member is going to help with the various roles.
A completed will or trust is not the end of the conversation but the beginning as there is so much more to discuss than just distributing property. The family meeting should include a conversation about medical care, financial management, doctors appointments, respite care, etc.
This article outlines the elements of a family meeting: https://www.caregiver.org/holding-family-meeting
I encourage anyone who is caring for a loved one to read this article and have a meeting to make sure everyone is on the same page.