How do I add my wife's checking account interest to my taxable account?

Yes, you can report your wife's bank interest income on your joint return in TurboTax. Here's how to do that:

1. Sign in to TurboTax. 
2. Select Income & Expenses, then Pick up where I left off or Start.
3. Select Start or Update to the right of Investments and Savings (1099-B, 1099-INT, 1099-DIV, 1099-K, Crypto).
4. Answer the first question Yes, or if you already have some income here, select Add investment.
5. Select Enter a different way. 
6. Select the Interest tile and Continue. 
7. Select Type it in myself at the bottom. Enter the bank's name.
8. Enter your income in box 1 or 3 as it is on the 1099-INT.
9. If you have other boxes filled in on your 1099-INT, check the box next to My form has info in other boxes (this is uncommon).
10. Complete the rest of the form, then Continue.
11. Answer the remaining questions based on your situation.