Is it permissible to propose to a girl who has previously received a proposal from another suitor?

If a woman has accepted her suitor, it is not permissible for anyone else to propose to her, because the Prophet, peace and blessings be upon him, said: "A man should not propose over the proposal of his brother until he marries or gives up." However, if acceptance has not yet occurred, there is no harm in it, as is clear from the hadith (definition) of Fatima bint Qais, and Al-Shafi'i's interpretation that the engagement is open to suitors as long as the woman has not given her consent.