How do I receive my wife's 2017 tax return?

Did you file separate returns?   Or was that before you got married?  Did she use Turbo Tax Online?  She has to log into her account.  That's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/

If you used the Desktop CD/Download program then the only copy is on your computer and not saved or stored online.

Or get a copy from the IRS.

See this IRS website for transcripts - http://www.irs.gov/Individuals/Get-Transcript

For a fee of $50 you can get a complete federal tax return to include copies of W-2's from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf

See this IRS Tax Topic - http://www.irs.gov/taxtopics/tc159.html