Line 6c of IRS Form 1040 asks for three different types of dependents.
- Number of children on 6c who: Lived with you
- Number of children on 6c who: Did not live with you due to divorce or separation
- Dependents on 6c not entered above
If the relationship is entered as any of the following, and neither of the boxes "Check if dependent child did not live with you due to divorce or separation" or "Check if dependent was a resident of Canada/Mexico" are checked, and there are months entered as "Months dependent lived with you", then the dependent will be counted in the first line Number of children on 6c who: lived with you
Please note that as the IRS only allows certain text for describing relationships for electronic filing, that is also the text that will print on line 6c of Form 1040 (i.e. sister is used for both sister and stepsister) and is correctly done per the IRS instructions.