Thanks, the box is marked and there are no errors. The issues lies with the fact her income is below 100% the federal poverty line and that she opted not to receive monthly PTC. I added $1 as a monthly advance payment of the PTC and she received the PTC for the whole year just to test my theory.

It seems wrong that just because she choose to not receive monthly advance payment of the PTC every month and to receive it at the end of the year, we cannot calculate the PTC for her. 

from 8962 instructions: (Pg. 8, Line 6.)

You may qualify for the PTC if your household income is less than 100% of the federal poverty line and you meet all of the following requirements.
•
You or an individual in your tax family enrolled in a qualified health plan through a Marketplace.
•
The Marketplace estimated at the time of enrollment that your household income would be at least 100% but not more than 400% of the federal poverty line for your family size for 2019.
•
APTC was paid for the coverage for one or more months during 2019.
•
You otherwise qualify as an applicable taxpayer (except for the federal poverty line percentage).

She meets the exception for all except he last part because APTC was not paid for 1 or more months in 2019, she cannot take the PTC. This is a difference of almost $9,000 for her just because she thought she would receive the PTC automatically at year end when she files her return.

Thank you