No, unfortunately a green card holder cannot petition for a sibling.

For assistance with form completion, it is best to work with an attorney.

Does she still need biometrics done?

No, there is no additional fee for your EAD and biometrics should not need to be done again if previously completed with the I485.

What is the basis for your application for permanent residency? More information is needed about the incident in question as well. Best to consult...

Yes, certified translations from Mexico should not be a problem.

You will need a full review of your immigration history in order to provide a meaningful answer.

Yes, that is acceptable for you to act as preparer.

This may be in error if name was not changed. You may contact USCIS for further clarification.

Write a formal letter to USCIS requesting the withdrawal.

You should file where you both will he residing; if in CA, indicate accordingly.