When you are entering your 1095-A into TurboTax you will first enter all of the information that is on the form.  You'll enter it exactly as it appears there.  Then, on the next screen, you will tell the system that you shared the policy with another taxpayer that is not on the return.

The system will ask about your child.  It'll want the social security number and the allocation start and stop months (which are January to December for you because you split it the whole year).  Then it will ask you for the percentage of all the numbers that you entered that you want to allocate to your own tax return.  

In order to find that percentage you need to figure out the percentage per family member.  If there are only the two of you then that's easy - 50%.  If there are 3 then it's 33.3%, four 25%, five 20% and so on.  Subtract one family member from the total then enter the rest in the system.  For example, if you have four family members and you're allocating with one child then you would each be worth 25% of the total so you would subtract the 25% for the one child who is not there and enter 75% into TurboTax.

Then your child - using the numbers from that example - would enter the 1095-A into their tax return and allocate 25% of the total onto their taxes.

@NnyJ23