My wife is a bartenbder. It's asking about unreported tips. But in her W-2 box 7 (Social security tips) it shows 3171.87. Does that mean the employer already added tips?

Yes, that means her employer already added tips. The question on unreported tips is asking if she made more tips than what is reported on the W2. Is the amount on the W2 reflective of all the tips she received?

No it is not.

Then, she should report the additional tip income on her tax return.

Thank you.

No problem.