You are never required to claim a dependent. However, there is a legal requirement that if your daughter can be claimed as a dependent by someone else, she must answer "yes, I can be claimed as a dependent" on her tax return. This will disqualify her from certain tax benefits including stimulus rebates.
Meanwhile, your daughter will always file a tax return for income in her own name, even if she can be claimed as a dependent. Filing a tax return does not, by itself, affect her ability to qualify as someone else's dependent, but her income and age may affect her status.
From your point of view, there is no benefit to not claiming her as a dependent if she qualifies, except in the case where she is a college student under age 24, and the parents' income is too high to qualify for the American Opportunity Tax Credit. In this case, if the child can be claimed but is not claimed, the child may qualify for some AOTC that the parents don't. This is the only tax situation where you may benefit from not claiming a child who can be claimed.
