First off, sorry to hear about the present hospice situation and I hope your daughter is on the mend.
I didn't see a specific note about this in the CoC or on the delta website. I've had good experiences on a case by case basis requesting changes/cancellations by using similar guidelines to what's requested for Medical Fares earlier this year when my grandmother was hospitalized, and then later passed away.
From Delta's page on "Medical Fares"
Originally Posted by delta.com
1. Hospitalization/Hospice:
The ill family member is hospitalized or under registered hospice care. The family member may be at their residence, provided they are registered in a hospice program and that their status may be verified. The visiting passenger must travel to and from location of hospital or hospice or hospice home. (Exception: On a case-by-case basis, Delta may allow travel to a city other than the location of the hospital, but is nearby so passenger can meet family members and drive to the hospital.
Required Information: The name and relationship of the ill family member in the hospital/hospice or at home under hospice care, name of hospital/hospice/ at home hospice care and phone number.
In both cases, the tickets were converted to an eCredit minus the change fee, and I had to call in to use the eCredit and was directed to request the change fee be waived due to a previous family medical emergency/death causing the cancelled travel. In one case they asked for the Med Emergency info again at rebooking as it hadn't been recorded in the file (family member's name, hospital, hospital phone number). Also to note, DeltaAssist was able to take care of this for me, and that provides some written correspondence on this since Twitter DMs are logged.
If your ticket value is <Change fee you won't have an eCredit noted in your DL.com wallet, so save the ticket number for when you go to rebook as the phone agent will need the ticket number to be able to access the value of the ticket for rebook. As an aside, one of my eCredits was "invisible" in my DL wallet as ticket value was <Change fee, whereas the 2nd eCred shows as ~$75 (TicketValue-Change Fee)... but I was told will be honored at original value and they'll waive the change fee once I go to rebook.
Also kudos to Delta for being understanding and accommodating during an obviously stressful time for passengers.