Thank you @Hal_Al - yep, it is very complicated for "civilians" like me. As I mentioned in my earlier questions and follow ups, all of 529 withdrawals were qualified (and were not enough to cover kids' college expenses but was very useful). Additionally, while one kid was considered dependent (by IRS defn - as per TT - of an income of less than $5,000/yr!), the other one was not. Additionally, neither of them qualified for any sort of educational credits, so those credits didn't matter. Anyway, taxes were filed a while back and I followed @AmyC 's advice which came on a timely manner and was very helpful. Thanks again.
Best wishes,
-Sb
