If you filed the Form 8379 by itself after a joint return has been processed by the IRS, then processing takes about 8 weeks.
If you filed Form 8379 with your original return, it can take up to 11 weeks to process an electronically-filed return or up to 14 weeks if you filed a paper return. More details are here https://www.irs.gov/taxtopics/tc203.html
If it's been longer than the number of weeks mentioned above, you can call the IRS to check the status of it. You can call the IRS tax refund hotline at 800-829-4477, Monday - Friday, 7:00 a.m. to 11:30 p.m. After you successfully file your return with TurboTax, it's handled from there by the IRS and/or your state. They process returns and handle refunds.
