Can i claim my college aged daughter on my taxes even if she claims herself

If you "can" claim her then  she needs to amend to un-claim herself by checking the box that another taxpayer can claim

While nobody can be compelled to claim a dependent, a dependent cannot claim them self if they can be claimed by another tax payer - the tax law does not allow that.

That is why there are two questions in the interview - *can* you be claimed as a dependent by another taxpayer, and *were* you (or will you) actually be claimed by that taxpayer?

In both cases the dependent will not get their own $4,505 personal exemption. If the answer to the second question is "yes" then the taxpayer claiming the dependent gets it, if the answer is "no" the exemption is lost, but the dependent is then allowed to claim certain educational credits that cannot be claimed by a dependent if they are actually claimed.

See IRS Pub 17 Personal Exemptions - Your Own Exemption
https://www.irs.gov/publications/p17/ch03.html#en_US_2016_publink1000170848

You can take one exemption for yourself unless you can be claimed as a dependent by another taxpayer. If another taxpayer is entitled to claim you as a dependent, you can’t take an exemption for yourself even if the other taxpayer doesn't actually claim you as a dependent.

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---Tests To Be a Qualifying Child---
(Must pass ALL of these tests)

NOTE: If a child passes all of these tests he must say “yes” on his/her own tax return (if he/she files one) that another taxpayer CAN claim him/her as a dependent even if they DO NOT claim him/her)

1. The child must be your son, daughter, stepchild, foster child, brother, sister, half brother, half sister, stepbrother,stepsister, or a descendant of any of them.

2. The child must be (a) under age 19 at the end of 2016, (b) under age 24 at the end of 2016 and a full-time student* for any part of 5 months of 2016, or (c) any age if permanently and totally disabled and must be younger than you (or your spouse if filing jointly).

3. The child must have lived with you for more than half of the year (There are exceptions for temporary absences such as school, illness, business, vacation, military service).

4. The child must not have provided more than half of his or her own support for the year.

5. If the child meets the rules to be a qualifying child of more than one person, you must be the person entitled to claim the child as a qualifying child.

6. The child is not filing a joint return.

7. The child must be a U.S. citizen, U.S. resident alien, U.S. national, or a resident of Canada or Mexico

 *A full-time student is a student who is enrolled for the number of hours or courses the school considers to be full-time attendance during some part of each of any 5 calendar months of the year.

See IRS Publication 17 for more information.

https://www.irs.gov/publications/p17/ch03.html#en_US_2016_publink1000170876

A person can only be claimed on one tax return. As others have indicated, the real question is should she have claimed herself. If not, she should file an amended return, unclaiming herself. You do not need to wait until his amended return is fully processed, to claim him on your return. But, you cannot e-file. You will have to mail in a paper return. Most unmarried college students, still living at home, should not be claiming themselves. 

Why did she even file a tax return, if she is still financially dependent on you? One possible reason is that there's a new urban myth among college students that says they can get a $1000 from the government just for filing a tax form. For most of them, they simply aren't eligible. A student, under age 24, is only eligible for the refundable portion of the American Opportunity Credit if he supports himself by working. You cannot be supporting yourself on parental support, 529 plans or student loans & grants. You must have actually paid tuition, not had it paid by scholarships & grants.  It is usually best if the parent claims that credit. 

 Here’s yet another tax issue. You state that she received a scholarship from college that went to tuition expenses. That normally means neither you or she qualifies for the tuition credit. But, there is a tax “loophole” available. The student reports all his scholarship, up to the amount needed to claim the American opportunity credit, as income on his return. That way, the parents can claim the tuition credit on their return. They can do this because that much tuition was no longer paid by "tax free" scholarship.  You cannot do this if the school’s billing statement specifically shows the scholarships being applied to tuition or if the conditions of the grant are that it be used to pay for qualified expenses.

Using an example: Student has $8,000 in box 5 of the 1098-T and $8000 in box 2. At first glance he/she has no taxable income and nobody can claim the American opportunity credit. But if she reports $4000 as income on her return, the parents can claim $4000 of qualified expenses on their return.