Download the PDF of the 2015 tax return from the 2015 Timeline. There will be a Wages, Salaries & Tips worksheet that shows income for the taxpayer and spouse among other separate worksheets for income.
Sign onto your online account using this TurboTax website - https://myturbotax.intuit.com/
You have to sign onto your 2015 online account using the exact same user ID you used to create the account.