It is uncommon for J-1 visa holders to be granted a second extension of stay.
The purpose of the J-1 program is cultural exchange, which has a limited duration. Multiple extensions prolong the temporary stay, diverging from the original intent.
However, in rare cases, a second extension may be considered if the sponsor files again with extensive documentation explaining why additional time is necessary to complete the program.
The request still may not be approved, as one extension is usually the maximum allowed. Once you obtain your marriage-based green card, you will no longer need temporary J-1 status extensions.
Second extension requests require experienced legal guidance to have a chance at approval.