Is it permissible to help her with money to relieve her distress, for the sake of Allah, without knowing the details of her financial problem?

What you wish to do in helping your friend is among the greatest acts of righteousness and the best of good deeds, due to the encouragement to strive in fulfilling people's needs. The Prophet, peace and blessings be upon him, said: "A Muslim is the brother of a Muslim; he does not wrong him nor does he hand him over. Whoever is in the need of his brother, Allah will be in his need. Whoever relieves a Muslim of a distress, Allah will relieve him of a distress from the distresses of the Day of Resurrection. Whoever covers a Muslim [his faults], Allah will cover him on the Day of Resurrection."