Hold on a second. Are we talking about that $28,000 being total income (1040 line 22), AGI (1040 line 37), or taxable income (1040 line 43)? If it's total income, then yeah, she's an idiot. But if it's AGI or taxable income and she's got a whole bunch of other credits that reduce her liability to less than $7500 before this one kicks in, then that's more reasonable.
(Who am I kidding? It's probably total income...)