Try to apply on your own and see what happens. In your case since you are still married and jointly filing and especially also because you have a child together, approving your case shouldn't be too difficult.
Make sure to follow the instructions and attach as much documentary evidence as possible, from the day of your marriage to present.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
Although it is not required to hire an attorney in any immigration proceeding, sometimes it's best to make a little investment to make sure the process goes well. If you're game for trying on your own, MAKE SURE TO READ THE INSTRUCTIONS CAREFULLY. A simple error could end up delaying the case or worst result in a denial for failure to meet a technical requirement.