I need to know questions to ask my lawyer about open adoption rules

I don't understand your question. You are represented by an attorney who should be able to advise you of your options. Your questions should be based on what needs to be done to reach your desired result(s). Is your later comment that you are "taking it to trial" based on your conversations with your attorney? If you trust your attorney, you should follow his or her advice. If you do not trust him or her, then you should find another attorney who should be able to provide you guidance.

I am assuming your sister is adoption you child. An open adoption allows for visitation with the child even though you would no longer be the child's mother. Your name would be removed from the birth certificate. You should ask your attorney about some of the following items. 1. Whether guardianship or adoption is a better option. Adoption is a big step so make sure you explore all your options 2. Ask about child support 3. If you can structure the adoption so you have scheduled visits 4. What happens if your sister won't let you see the child or wants to move far away. 5. What if the child wants to live with you when he/she is older.