How long it will take for the whole process?

You may check processing times on the USCIS website. Presently most are being processed within 6 months to 1 year.

Probably means that the visa is ready to be issued but a review of your process and notices is required to make an accurate assessment.

A review of your filing is needed to determine what evidence will help support the petition. For instance if it is a joint filing and there has...

The temporary stamp is as valid as the card. You will need a valid passport along with the valid I-551 stamp or card for return to the US.

My daughter is in H4 visa and her visa is expired on 27th July'17 & filed for an extension on Sep 6th,17. Is this an issue?

If the extension was filed before her authorized stay expired, see I-94, that is okay. The visa is not controlling as to time stay is authorized.

What are the supporting doucuments for form DS-260 ?

You may find the requirements on line on the DOS website or they should also be in the materials for the NVC

You may be asked anything that will or may be connected to the petition and application. You should consider contacting and working with an...

When can I change the employer after I140 approval?

The I -140 approval does not authorize employment.

I got my permanent resident through my son; however; I have a disabled child who depends on me?

More information is needed, however, parole is a possibility and there may be others.

Follow the instructions for the form I-751 carefully and fully. The required documentation is included in the instructions.