Bets, Delta was running the Netherlands Covid-Tested Flight program, which was supported by reps here in NL. But in my research, I've discovered that's just ended - so back to square one. You're correct in your posts about "planning ahead," To find a COVID testing option that (1) meets the NL requirements, (2) is open at the time she needs the test, and (3) can put the results in her hands before she has to check-in... it's a challenge.
Her first flight departs at 1.1.20 AM from ATL - so check-in about 9.20 AM. She connects at EWR and her flight to NL takes off at 6.15 PM. Thus, sometime between 6.15 AM and 9.20 AM on the morning of her departure, she has to take and receive negative results on a test to meet the NL 12-hour rule. And in that same period, turn in her rental car, get through the ATL traffic, the ATL airport, etc. It's certainly a challenge. The "turn-around-time" on the 12-hour window is tough, and yes, it's more expensive.
This almost forces you into the 2-test option, which frankly, makes no sense. France talks about opening up for tourists; my wife lives here, pays NL taxes, has a Visa... and can't even get home. There's not a lot of uniformity in the European approach as of late. These tight restrictions also apply to transit folks simply connecting through AMS. As a result, AMS has turned into a ghost town.
I have not found a 12-hour answer yet. (Don't you wish they'd simply provide quick-testing at the airport if they're going to make these rules?). Currently, we're working on the "2-test, 24-hour-and-72- hour" option in order to get her home. If the NL gov't would just drop the 12 or 24-hour requirements they added a few months ago and simply go with the 72-hour requirement - which many countries use - this would be all so much simpler. As it appears now, it will be expensive as her NL healthcare does not work in the USA.
Of course, compounding the problem is that none of us here in the NL are vaccinated. She hopes to get a J&J jab while in the USA. Even if she is successful in that endeavor, under the current rules, she will still need one or two negative tests to re-enter the NL. And then, because of new NL quarantine rules - which don't even start until May 15th - she will have to quarantine for 10 days unless she wants to take another test after 5 days. And this in a country that has incredible internal problems handling the COVID outbreak.
For those of us that live here with EU passports or visas, it's frustrating to deal with these stringent entry requirements while politicians pontificate about opening Europe to tourists.