I got a CP2000 about 2014 1099-MISC that I totally forgot about. Can I fill out an amendment form from Turbotax?

My wife worked briefly as a music instructor in early 2014, and in 2015 when I filed for 2014 tax, I totally forgot about her "self-employed job as a music instructor. It was through this company, and we never received 1099 form from them.

Today, I got CP2000 form from IRS about this $7173, unreported 1099-MISC, and I owe them $3023...

First of all, I never received 1099MISC... AND how can tax I owe be almost half of the unreported income? I know there are deductibles I can make since she worked and prepared her lessons from home.

Can I still fill out an amend form through Turbotax? or I do have to pay 3023 full amount?