Hmmmm…usually people raise their hands to ask questions. So, who should ask the question so that it doesn’t look suspicious to the husband? Her husband and BIL wouldn’t dare do it. Her sister COULD do it…but risk offending both men. The OP wouldn’t do it.
Unless…the Imam answers questions that are written on paper…that would be more anonymous…cuz it could have been asked by anyone. OR…if she could get someone else to ask the question for her.
Hmmm…what if she were to tell the imam that she has noticed how some women and men (don’t name them) are openly talking to one another about their sex lives…and this issue makes her feel uncomfortable…and could he please do a general khutbah on the issue. That way…the Imam won’t know for “sure” that the issue deals with her husband.
But she’ll have to make sure that her husband attends it.