No, the rules have not changed. You incorrectly
claimed you daughter last year (2016). Part time student is the issue. There is
no income limit for FULL TIME students under age 24, who still live at home (or
are away at school).
The dependent interview is tricky and you
answered something wrong, last year. TurboTax is correctly, this year, not
qualifying her as a dependent because
her income is over $4050 (2016-17) $4150 in 2018.
There are two types of dependents,
"Qualifying Children"(QC) and standard ("Qualifying
Relative" in IRS parlance even though they don't have to actually be
related). There is no income limit for a QC but there is an age/student status limit, a
relationship test and residence test. Only a QC qualifies a taxpayer for the
Earned Income Credit