It's hard to say, you did not provide enough information.
Because your daughter is 18, you could claim her as a dependent if she lived in your home more than half the year, and you provided more than half her support. It sounds like that is probably not the case, since you say she supported you. However, I don't think two people can live on $15,000 (or teach me how) so I wonder if you have child support, social security, alimony, government support, or were living off savings. If you were using your savings or social security benefits to support the family, you might have provided more than half your daughter's support, but if you had alimony, child support or government assistance, you probably did not provide more than half her support. But only you know that.
If you claimed your daughter as a dependent, you would get very little tax benefit with only $800 of wages. A few dollars of EITC and a few dollars of the Additional Child Tax Credit.
Alternatively, your daughter could claim you as a dependent if she paid more than half your support, and you have less than $5050 of taxable income (counting not just wages, but also interest, dividends, or pension withdrawals). Here again, the more than half the support comes into question. If you received support from outside the two of you (government, charity, alimony, child support, etc.) then even though your daughter earned more, she might not have paid more than half your support.
Again, however, your daughter would get very little tax benefit from claiming you. A few dollars of the dependent credit, and maybe a few dollars of EITC. (She could qualify for the $500 credit for "other dependents", but at $15,000 of income, her tax owed would be less than $100, so the credit would only pay up to the tax she owed and not more. EITC could give her a little bit of a refund.
The only way to know for sure is to make test returns both ways, but I think that your daughter claiming you (if the support test allows it) will work out better, since your income is so low that you don't even need to file a tax return. If you have outside support so that she can't show she paid more than half your support, then she would file single with no dependents and you probably don't need to file at all, unless you want a refund of the $33 withholding.
