How do I add the second person's information (S.SN. and etc.) if i had two more people listed on 1095-A and they both are filling on their own?

You don't enter their information. The other people will each indicate that he/she shared this policy with someone who is not on his/her tax return. You will indicate the same thing on your return.

TurboTax will ask you how you want to allocate the policy amount. When allocating any Advance Credit received, you have the option to claim 100% of the 1095-A on your tax return, or you can allocate part of it to your nondependent.  The allocation can be anywhere from 0% to 100%.  You all must agree to the allocation.

To enter your 1095-A form:

• Login to your account.
• Select Federal from the left menu.
• Go to Deductions and Credits.
• Scroll down to Medical.
• Select start next to Affordable Care act ( Form 1095-A)
• Enter the form and continue to the screen to allocate the amount between you and your children.

Note: You qualify for the credit if:

• Your health insurance plan is purchased through Healthcare.gov or a state Marketplace
• Your household income falls between 100% and 400% of the federal poverty level for your household size
• You don't file as Married Filing Separately (with exceptions for victims of domestic abuse and spousal abandonment)
• You can't be claimed as a dependent by another person

Source: MayaD