The tax consultant who made the mistake in your original tax return should prepare the amended return for you at no charge. The amended return uses the original return as a starting point. If the tax consultant prepares the amended return, she already has your original return in her computer. To prepare an amended return with TurboTax, you would first have to recreate your original return in TurboTax, making sure that it exactly matches the return that you filed, then amend the recreated return.
Approach 1 is the recommended approach. Approach 2 is not recommended for the reason that you mentioned. If the IRS makes any changes to your original return, and you have already filed an amended return, then you have a complicated mess that will be very difficult to straighten out.
