Did you use the same account to file your brother's and yours? If so, whomever you filed last would have overwritten the previous data. If this is the case your return would be under that account.
When you want to file multiple returns online you need to create a new account for each one. To file multiple returns please follow the steps below:
1. Make sure you have signed out of your TurboTax account
2. Go to https://turbotax.intuit.com/personal-taxes/compare/online/ to select the TurboTax product that will meet the needs of the filer
3. Create their account, set up a new login for the additional return (you can use your email address for up to 5 accounts if you want to receive e-file notifications)
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.