Will Allah unite a man and a woman who loved each other in this world but did not marry, knowing that both are destined for Paradise, and that the woman married someone else in this world?

If a married couple enters Paradise, the woman will be with her husband, based on the Almighty's saying: "Gardens of perpetual residence, which they will enter, and [also] those who were righteous among their fathers, their spouses, and their offspring." If a woman had more than one husband in this world and all of them enter Paradise, she will be with her last husband, as narrated by Al-Bayhaqi from Hudhayfah: "Indeed, a woman in Paradise will be with her last husband from this world." As for someone who proposed to her or loved her but did not marry her, she will have no connection to him.