Why am I being asked to add form 8839 "Adoptive child worksheet". I am claiming both of my biological children I don't see the form available to delete in "tax tool".

[AliciaP1]

The information you entered somewhere may have triggered another form first.  Try looking for Adoptive Child Worksheet or Adoption Carryover Computation Wksht when you are viewing to delete a form.  To clarify how to delete a form you can follow these steps in TurboTax Online:

1. Within your return, click on Tax Tools in the black menu on the left side of the screen.
2. Click on Tools.
3. Click on Delete a Form. 
4. Scroll down to your form and click Delete.
5. Under Federal in the black menu bar click Wages & Income to get back into your tax returns.
6. Proceed entering/reviewing your return.