If I only made $2500 all year, can I still claim my daughter on my taxes?

If your daughter is alive, under 18 or not disabled if over, and no one else is claiming the right to claim her (including her), sure.
It doesn't matter one bit what your income is.

To add to what joypulv said - no one else can be claiming you as their dependent.

Angel:

What about the other parent? Does she/she have a job? It might be more advantageous for him/her to claim the child, which you can allow in exchange for part of the refund or Child Tax Credit.

You need to provide complete details (where you live, status of the other parent, etc.) for us to provide concise and accurate answers.

He has a job, but owes back support, does not have custody or placement, or rights. He has min. visitation which does not even get practiced! There is no way I'm letting him claim her

Thanks!

No one claims me anymore!

'... under 18 or disabled if over,. ' was what I meant