"Her income is not a factor when claiming a dependent under the QC rules"
**Sort of.** As stated in item #4, "The child must not have provided more than half of his or her own support for the year." So, if the child had enough income (and if they used the income to provide >1/2 of their own support) they would technically not be a QC.
This is uncommon but can be used in some situations to their benefit. Example: If the child's federal tax liability is >than the dependent tax credit that the parents would receive for claiming her as a dependent, AND the parents' income is so high that it excludes the parents from qualifying for an education tax credit.
Keep in mind that the education credits pertain to EARNED income when asking about support but QC does not.
