Anna Pg

I know of a girl that left the US for the same reason (sick grandmother) while waiting for her EAD/green card, and was able to apply for the advance parole while outside the US and allowed back in. My suggestion is for her to go the US embassy where she is, with all the paperwork of her relatives illness and various NOA of her application in the US and see from there.

We are in the same situation. Staying the 14 days in Mexico. Hopping to be in New York next week. 

Hi!
 
Your flight cannot stop in a country in the Schengen zone. I considered Croatia but the changes are not suitable. 
 
I believe border control will know where and how long you have been in another country by your passport  
 
It seems the only suitable ‘work around’ at the moment is Mexico until more flights get going, or the border reopens!

If you're from the EU, you don't need to submit a passport when entering an EU country. 

But, when traveling to and from Schengen Area they need a valid national identity card or a passport. The Schengen Area is not necessarily the same as the European Union (EU). Not all EU states are part of the Schengen Area and not all Schengen states are part of the EU. As such, when you go to an EU member state that does not participate in the Schengen agreement, you will be subject to their completely separate visa, entry requirements and passport control systems. Ireland is an EU member state but is not part of the Schengen Area. Newer EU member states Bulgaria, Croatia, Cyprus and Romania are not yet part of the Schengen Area but will do so in the future. Conversely, Iceland, Norway, Switzerland and Liechtenstein are Schengen Area members that do not belong to the EU.
Diagram showing the relationships between various multinational European organisations and agreements:

Schengen Area is in Red. EU is in Light Blue.

Yes, true, but if you are from the a non Schengen EU country and you go to any EU country they won't even ask for your passport and if you do use your passport for identification, they won't scan it. So there's no way for the US to know you've been there. 
Nope, no stamp if you're an EU citizen. They will check your ID but they won't stamp it or scan it. 

You're right! One can always request a border officer to have a stamp affixed to their passport but there's the risk they say no. 

You can ask them for an exit stamp when leaving the EU and/or an exit stamp when entering Croatia. Many of us do "visa runs" from Schengen countries on the 89th day (since we are only allowed 90 days in Schengen) and need to ask for this so this is pretty normal. 

Per Croatian law any hotel needs to report any foreigners that are staying with them, when they arrived and when they will leave to their local police station. Private citizens are also required to do this (I had to when my fiance was visiting and staying at my apartment). Ask the hotel if they can provide you with a copy of the Form 8a “Registration and cancellation of residence or registration of change of address“. Of course you want the copy that has been signed and stamped by the police station. It’s an official document, we used it to prove that my fiance visited me in our K1 petition, so I see no reason why it should not be accepted. If you want, I can send you the link to the form so you can see what it looks like. Won’t even need to do a translation, because it’s both in Croatian and English.

 

Hello! 
 
The whole point of the Schengen Area is the freedom of movement between Shengen countries and this is why as EU citizens, we do not get our passports stamped when entering another Schengen country. Despite being a EU country, Croatia is not (yet) part of the Schengen Area so I assume you will have a stamp in your passport once at the Croatian border check point.
 
Regarding the flights to the US from Coatia with transit in Turkey, I don't know if you have seen it already but it was also discussed in another thread: 
 
(I've been considering going to Croatia as well - and I also see that we are going to the same city in the US -, but I ended up choosing Mexico!)
 

No passports have a chip in them now, they swipe your passport at border check points. The USA will know where you have been and how long for when they view the details on your passport. You don’t need to notify anyone else. 
 
This is why the flight cannot stop in a Schengen country as this will show on your travel history. 
 
Turkey is ok in terms of entering the U.S but I’m not sure about their own restrictions. I know they have banned international flights for now and you would have to check if rush includes lay overs. 
 
In terms of Mexico, yes there are always chances of added travel bans but with the land border already closed I feel less worried about the air border being closed too.

The above answers are correct, you cannot transfer through an airport in a country with restrictions.
I believe you can ask at POE for a passport stamp. As alternative you can keep your itinerary and also hotel receipt. CBP shares data with many countries so they might even have it in their database, but I wouldn’t fully rely on that.