Can my sister apply for my green card under f4? I am a Pakistani national married 42 years old.

Yes, your sister may file a F-4th preference petition on your behalf at any time. Note that there is a significant wait for visa availability...

Can one H1B Visa stamp combine validity of two I-797s?

The Consul should stamp the passport through the validity date of the most recent I-797. Consult with your attorney.

How would USCIS find out that LGBT asylee married opposite sex?

It could raise the specter of fraud in the previous asylum application, or perhaps could be explained.

If you file the I-131 and I-765 concurrently with the I-485, you do not need to pay the separate filing fees for the two forms.

When a person on Green card marries a girl on a OPT visa what will be her status post marriage?

Marriage alone does not change one's status. The husband could file a family based petition on the wife's behalf in this scenario, which could...

Can I do a part time while my 485 is pending?

You may work for any employer with you EAD, however, employment for other than your sponsoring employer could raise questions as to the viability...

What is the better option for a US pending asylee with a fiance in Canada.

If you are married to a Canadian Citizen, the Immigration Judge may consider Canada a "safe third-country" for you to go to reside. Consult with a...

Is it possible to appeal a denial of DV2018 DS-260 that has occured at US Embassy Warsaw (Poland)?

She needs to request reconsideration of the visa refusal at the Embassy.

If you are talking about her adjustment of status interview, you should be scheduled within 4 months after the biometrics in the usual case.

No, that would be a bad idea and cause the J-1 visa holder to violate status.