Verifying Waitress/Server Income

[Quandra Adams]

Do any of you ever require any supplemental information from servers or waitresses to corroborate their income? If so, what else do you ask for? Tax statements? 

I know servers can do pretty well making tips however I also know the pay (tips) is inconsistent so I don't want to overlook someone due to the financial situation but I also want to be sure that I'm looking in the right places to verify that the income is what they say it is.