Brockman

I used the services of TT member @Kilkenny for the same exact reason (marriage and birth certs for Berlion Standesamt) and I very highly recommend her.

Just curious, what leverage does Kita A have on you? What could the consequences be if you just walk away and ignore them?   At the end of the day, isn't the Jugendamt the authority on these matters? If the Jugendamt says that you're good to go, and Kita B says you're good to go, and Kita A is the only one saying you're not, then what could happen? Even if they decide to report you to the Jugendamt, and the Jugendamt agrees with you (and provided you with the Gutschein), then what could come of that?   If you're really worried about Kita A (which, sorry, to me it is baffling why you would be, since it seems it is only their word, they are not providing proof this is the rule, nor are they holding a Gutschein for ransom), you should go to the Jugendamt and explain this predicament, and ask for something in writing that says you're free and clear to attend Kita B without waiting 3 months, and post a copy of it to Kita A along with a kind note that your relationship with them is over and there is no need to contact you ever again, and that further correspondence from them will be not read and thrown in the trash.

It seems as if you are on top of things and already checked with the Jugendamt. The Jugendamt is the law, so I would go by what they say. Why does it matter what A says, why not just ignore them if you've already confirmed with the Jugendamt and B and neither have an issue? Is A holding your Gutschein for ransom?

Aside from the fact that it seems you might not meet the US residency requirements, I think it's more hassle that it is worth, and that since your life is focused in Germany and you have a child, you should finalize the divorce in Germany. I got divorced in the US from my non-US citizen wife. Since I wanted to remarry a German, in Germany, in order to get the proper documents, I needed to get all of the US (NYS) divorce paperwork translated to German, with an Apostille. Then the Bürgeramt had to take my paperwork through another process to get the paperwork formally recognized in Germany (this was done through one of the courts in Berlin), and that took a few months. Between translations, Apostilles, delivery costs, and the formal court recognition, the costs will probably end up being higher. Just get divorced in Germany.

I have a Google Voice account (https://voice.google.com) with a US mobile phone number and it works for the various US-based services (bank, credit card, investment accounts) I use which require two-factor authentication.

If this is about changing your tax class, I haven't seen that you've consulted the Finanzamt yet. Why don't you try asking them?