What is the ruling on the money and gifts a woman acquired from previous relationships before her repentance and marriage, knowing that she used to give charity from them and help those in need? And is it permissible for her to keep what remains of them and utilize their proceeds?

What you mentioned about your friend is a great error and an act of ingratitude towards Allah's blessings, and praise be to Allah that she repented from it. As for her helping people and the poor and giving charity, this will not benefit her with Allah, because charity from ill-gotten wealth is not valid, due to the Prophet's (peace be upon him) saying: "O people, Allah is good and accepts only what is good." What is incumbent upon her for the completeness of her repentance is to dispose of this money in charitable causes and public welfare projects for Muslims with the intention of getting rid of it, not with the intention of charity. It is permissible to spend it on her needy family and relatives.