Is not greeting a bullying girl considered abandoning her? And is not greeting a girl with whom you had an unlawful relationship, then repented, also considered abandoning her?

It is permissible to shun the two girls if maintaining ties with them causes harm to you in your religion or worldly life. One of them harms you, and the other was in a forbidden relationship with you and has not repented. Ibn Abd al-Barr said: "And often, a beautiful severance is better than a harmful association." However, if the one who harms ceases her harm, and the other repents from what is forbidden, and there is no longer any harm to you in maintaining ties with them, then shunning them is not permissible at that time.