Does a woman sin if she does not inform her family of the doctor's suspicion of a tumor, and is she obligated to inform them if the disease is confirmed?

There is no sin in concealing illness from relatives, especially if it is doubtful, and it is a sign of perfect patience. It is permissible to inform them when it is confirmed, but concealment is preferable. If informing them benefits you, such as assisting with treatment, then it is advisable to inform them. Manifesting affliction without complaint does not contradict patience. Complaint contradicts beautiful patience, which is free from restlessness. Patience is restraining oneself from what is disliked, refraining the tongue from complaining, and awaiting relief. It is recommended to seek help through prayer, supplication, charity, and drinking Zamzam water.