Get your taxes done using TurboTax

@kimoleahi - with the Online version you pay for each tax return that is submitted.

 

with Desktop, yuou can submit as many tax returns as you want for the cost of the original software.  

 

So Desktop is much cheaper if you are doing multiple returns.  You can efile both federal returns at no extra charge (the limit is 5 per IRS rules) but there is an additional charge of $20 per return to efile (but you could always print the state return and mail it in).  The state software normally comes bundled with the price of the original CD.  

 

Yes, both your return  and your sister's return will pre-populate the state information as you enter information into the federal return. 

 

one of other benefits of the desktop version, is since you have already paid for the software, you can review the return as you populate it.  with the online version, you can't do that until you have paid for the service.