Yes, you may bring a US immigration lawyer to the green card marriage interview. Nevertheless, your lawyer cannot answer the questions for you or your spouse. The presence of your immigration lawyer can bolster your confidence and protect your legal rights during the interview. Additionally, in case the USCIS officer requests a document from your file, your green card lawyer NYC can probably find it faster than you can or, if it is absent, provide a better explanation.
If you hire an immigration lawyer solely to accompany you to your green card interview, you should ask him examine your files in advance to determine whether you have everything you need, including updated financial documents for the Affidavit of Support and other documents such as your criminal record.