Yes, If she is under the age of 24 and lives with you. A child of a taxpayer can still be a “Qualifying Child” (QC) dependent, regardless of his/her income, if she meets the qualifying child rules. See the other reply for rules.
There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income. They are interrelated but the rules are different for each.
If she does not meet the QC rules, then there is an income test to be a qualifying relative.
