I do feel bad for your mothers circumstances. But she entered into a contract and defaulted.
The facility is in business to make a profit off renting storage space. If your mother isn't paying then what are they to do? They need that unit emptied to rent to someone else.
Now, they can just donate goods to charity. This means you still loose your belongings and still owe. Then you have collections, interest, bad credit......
Or they auction it off, in which case, we are paying off, partially paying off or in some cases paying off AND you make some money.
I don't know anyone in my crowd that won't give back "memories" beyond the personal stuff unless that "memory" item is high value......in which case, your mother could have sold it herself and paid her debts.
I've run into people that have said "oh...that was my grandmas....."
Hey, it's life. You do what you have to. If you value possession of a material object over selling it to pay your debts or putting food on the table you need to examine your priorities. I personally don't own anything I wouldn't sell to take care of my family and pay my obligations.
I was at an auction once that this man and wife were giving a sob story, didn't have money to pay for unit. I found out they had a $50 unit. Were only into facility for an out $200. In the unit was a set of big'ol swamper tires on rims. Totally would have paid off debt, plus had extra, plus wouldn't of needed unit anymore since the tires took up 75% of it. Then on top of it, I saw them later at a Red Robin chain smoking (yeah, this was way back when) drinking and eating. I know I can't get out of RR for less than $30 with out drinks. So they can't pay $200 bill but can smoke, drink and eat out?
You see this enough and any guilt you had vanishes. Situations like your mothers are rare.
Also, think of it this way.
If you had a house and a friend lost his place and you let him put all his stuff in your garage and after several months, he hasn't paid a dime yet your paying a power bill to heat the garage so his stuff is safe, another person says to you: I'll give you $300/month to let me store my stuff in your garage......
How long before you asked the first one to get his stuff out?
So back to the question above, Jimmy. How should the facility handle defaults?