You can include the other income as cash on your return and you will not need the 1099.  To do so, follow the steps below.

• Go into your account with Turbo Tax (TT)
• Select Federal Taxes, then
• Select Income and Wages, (see screen shot below) then
• Scroll down and select, Self-Employment Taxes, then
• The screen that will come up; Tell Us The Type Of Self Employment Work You Do, here you can put in Secret Shopper. Select continue
• The next screen will be Let's Get Income For Secret Shopper here you will select 'Additional Income'.  This is for cash income.  Screen shot below.
• Then continue as you normally do with your return.