US Immigration from Tajikistan

Okay, Last year I filed "Married filing separately" with the Chaos this year I was in fact supporting my wife and (step)daughters, as she was not working for several months. They have not entered the country yet. I am considering, filing married jointly for this year, as her income is effectively $0. Can I file for a Tax Id number for her? Do I also need to do so for our daughters? to be able to claim all as dependents.

I'm not sure where to put this my wife is wanting to get Braces for Our(her) daughters. is it possible to have them put on in Russia, and follow-up here? I know I will be adding them to My insurance once they arrive. I am just not sure what will happen if they already have them from another country.

Okay My wife went to ask for Police Clearance from Russia about 13th of August 2020. even though she is a Tajikistan citizen. How long should it take to get them?

My Wife is From Tajikistan, currently in Moscow. We need to get Police certificates form both Russia and Tajikistan. With current travel restrictions, unable to get back to Tajikistan. Does anyone know if she/we can get them via E-mail? The postal system in both Tajikistan and Russia is mostly nonexistent. or could she have a family member get the document for her? maybe using a "Power of Attorney?" It does state on the https://travel.state.gov/content/travel/en/us-visas/Visa-Reciprocity-and-Civil-Documents-by-Country/Tajikistan.html site that any public notary can make a certified copy. Do we try and hire a notary or what? My mind is spinning thinking of what to do.

Trying to get everything for NVC My Wife is currently in Moscow, she is a Tajikistan citizen Police certificates needed. For both Russia no problem, but Tajikistan with travel bans due to COVID can not travel. can they be obtained online?