The amount of withholding or claiming Exempt on a W-4 has absolutely no effect on whether you can claim a dependent on your tax return. It only effects the amount of taxes that are withheld for the income received. See IRS Form W-4 - http://www.irs.gov/pub/irs-pdf/fw4.pdf
From IRS Form W-4 (2014) - Note. If another person can claim you as a dependent on his or her tax return, you cannot claim exemption from withholding if your income exceeds $1,000 and includes more than $350 of unearned income (for example, interest and dividends)
Since your child is under the age of 19 and will be receiving earned income assuming being reported on a W-2, she will not have to file a tax return if the income is less than $6,150 in 2014. If over $6,150 then she would have file a return and indicate on the return that she can be claimed as a dependent on someone else's return. Also, you do not report the dependents earned income on your tax return, either from wages reported on a W-2 or from self employment that may be reported on a 1099-MISC.
