I think I goofed on my 2019 Business Inventory. Should I file an amended 2019 return?

In 2019 I reported no income on my wife's jewelry business because I didn't think she had any as we had just moved into our new home and had way too much else to do with our time (like raise a toddler and she went back to teaching). We still had her inventory from the previous year, which was about $3600, but no income. I'm not sure how it happened, but I did not provide a value for the end of year inventory for 2019, so line 41 of Schedule C is blank. 

I discovered this issue while working out my taxes for this year and realizing that there was no inventory amount from 2019 draw from as the beginning inventory for 2020. I also found out my wife actually made around $400 from online sales last year that I missed and apparently failed to report. 

I know that I need to mark the little box at the bottom of the inventory input screen that says my 2019 EoY inventory is different from my 2020 BoY inventory, and I know about what I should put in the explanation.

 

My question is: Does this warrant an amended 2019 return, or is this such a small amount that the IRS doesn't care? What do you tax professionals recommend?