IRS sent me a letter requesting a completion of Sch. SE for $11k house sitting fee that I reported in 2018. The fee is not rent. Should I file the SE?

The house sitting fee is from a friend of my daughter who is maintaining its upkeep until my daughter returns from her school's 2 year internship. I reported the fee as other income on my 2018 taxes.   Its a bartering agreement, the person in the home takes care of it for 2 years and pay only a $1000 a month.  The fee is less than rental market rates and all insurance and utilities are still in my daughter's name.. "