Can I save other returns to my account (my children)?

[Sargeant]

TurboTax Online is only good for one return. You would have to create a new account for each child, using the same email address but different usernames. Tip: If you're preparing multiple returns for family members, it's more economical to switch to the TurboTax CD/Download software, which lets you e-file up to 5 federal returns at no additional cost.

TurboTax Online: https://ttlc.intuit.com/replies/3288574
TurboTax CD/Download: https://ttlc.intuit.com/replies/3302087