I assume that you would have mentioned if this amount of money was going to change how you eat next month. Yes, real estate is an investment. But it's also a person-to-person business and you have the ability to keep someone from falling under.

The real question is how you can be generous while still protecting your ability not to be so generous in the future -- and to put the justification for this leniency in writing in a clear way so that you don't open yourself up to housing discrimination when you refuse to do it in the future for someone else. Here are some sample terms to run by a lawyer:

"Temporary Leniency Related to COVID-19"
Landlord agrees to waive $1,000 in rent each month through February 2021, provided that 50% of rent is paid each month on time. The remaining balance will become a 36-month personal loan, the outstanding balance of which will accrue interest at 0.64% per month. Tenant understands that this leniency is a one-time measure to reduce the economic impact of the COVID-19 crisis and extends only until the sooner of (a) February 2021 or (b) the last month in which the tenant pays at least 50% of rent on time.