My wife and I are filing jointly but I can't find where she adds her social security income. Do I simply add this into mine? This is confusing.

If you are filing a Joint return then the SS entry screen will have 2 columns for each of you.  Maybe you have to go back to My Info or Personal Info and check if you picked Married and filing together.  

Enter a SSA-1099, SSA-1099-SM or RRB-1099 under

Federal Taxes (Personal for Home&Business)

Wages and Income

Then scroll down to Retirement Plans and Social Security

Then the second line - Social Security (SSA-1099. RRB-1099) - click the Start or Revisit button

No, do not add it to yours.  You'll report it in the same place you did, but under her name.  Navigate to: Federal > Wages & Income  > Retirement Plans and Social Security > Social Security (SSA-1099, RRB-1099).

If you have indicated in the My Info section of the program that you are Married and are filing this tax return with your spouse. then you are filing as Married Filing Jointly.

In the section for entering your SSA-1099 both your names will be listed on the entry form.  See Screenshot

To enter Social Security benefits reported on form SSA-1099

Click on Federal Taxes (Personal using Home and Business)
Click on Wages and Income (Personal Income using Home and Business)
Click on I'll choose what I work on (if shown)
Scroll down to Retirement Plans and Social Security
On Social Security (SSA-1099, RRB-1099), click the start or update button