She is not a qualifying child. She is a qualifying person to qualify you to file as Qualifying Surviving Spouse. A qualifying child and a qualifying person are not the same thing.
There are two types of dependents, called qualifying child and qualifying relative. Your daughter cannot be a qualifying child (of you or anyone else) because of her age. There is no age restriction for a qualifying relative, but there is an income restriction. Your daughter meets all the requirements to be your qualifying relative except that her income is more than $4,700. But there is a special rule that the income limit does not apply to a qualifying person for Qualifying Surviving Spouse filing status, as long as she meets all the other requirements to be a qualifying relative. So you cannot claim her as a dependent because of her income, but you can use her as a qualifying person for Qualifying Surviving Spouse filing status.
