Can I file for someone else and deduct my fee from their return?

[Critter-3]

Yes but you must use a professional tax program (not TT) and be a registered ERO with the IRS  AND sign up to do this with a processing bank.  You must comply with all the rules and regulations set out by the IRS :  

https://www.irs.gov/e-file-providers/become-an-authorized-e-file-provider

[SweetieJean]

@Critter-3 is correct.  Turbotax is not licensed for use by paid tax preparers.