Yes. You can claim your daughter and grandaughter as dependents if you meet all of the requirements. It is ok that she filed a tax return as long as she indicated that she can be claimed as a dependent. If she did NOT indicate that she could be claimed as a dependent then your tax return will get rejected if you claim her.
If she did NOT indicate that she could be claimed as a dependent, she will need to amend her return and when you file your return, you would need to send it through the mail instead of efiling.
Please refer to the chart on page 12 of pub 501 to see if you meet the
requirements to claim them as dependents. Please note that there are
requirements listed above the qualifying child and qualifying relative
sections, and those requirements must be met as well. https://www.irs.gov/pub/irs-pdf/p501.pdf.