What should a married Muslim woman do to forget a disturbing matter of unknown origin?

The best remedy for anxiety is the remembrance of Allah, prayer, and avoiding idleness. For with the remembrance of Allah do hearts find rest, and in the Qur’an there is healing and mercy. Prayer is a comfort for the heart and a cure for worries; the Prophet, may Allah bless him and grant him peace, used to resort to it when a matter distressed him. As for idleness, it is a gateway to delusions and evil thoughts. The believer should not worry about sustenance or the future, but rather worry about his sins and shortcomings in fulfilling his duty to his Lord, repent, and hasten to do good deeds. Allah guarantees a good life for the people of faith.