My child is two months old her birthday is 12/23/2017

A child born (even on Dec 31) is considered to live with you the whole year.  So pick the Whole Year at the top of the drop down box.

There are six possible reasons; you aren't getting the Child Tax credit (CTC):

There are 6 possible reasons; you aren’t getting the Child Tax credit (CTC):

You must select that the child lived with you all year long. This is the reason you do not see the child tax credit. Any child born during the year qualifies as being in the home all year. Go back to the dependent section by clicking My Info in the left column. Scroll down to your dependent's information edit your child's information to get back to the question asking how long they lived with you. If you have already filed and been Accepted you will need to Amend your tax return.