My daughter (college student) earned ~$600 on W-2 for a part-time job, but I don't see a way to enter her W-2 info. How do I enter her W-2 info for tax filing?

You wouldn't enter her W2 on your tax return.  

If $600 was her only W2, she does not need to file (unless she had taxes withheld, which would be refunded to her)

She had taxes withheld, so she needs to file her own W-2, but I can claim her as my dependent still.
Please let me know if I am correct.

Yes. Full-time students under 24 who are your children and live at home almost always qualify as dependents.  When she files, make sure she answers "yes" to "can someone else claim you as a dependent?"

Even if she doesn't live at home, as long as you provide more than 50% of her support.

Appreciate your help!!