Who is the guardian of a girl born out of an illegitimate relationship, who lives with her mother and stepfather, after her biological father became religious?

Scholars differ regarding the lineage of a child born out of wedlock, and the most preponderant opinion is that he is attributed solely to his mother and not to the fornicator. Consequently, this child has no 'asabah (agnate relatives) from the paternal side. Some scholars are of the view that his 'asabah for inheritance purposes are only his mother or her 'asabah. Therefore, a child born out of wedlock has no guardian from the lineage side, and his guardian is the Muslim ruler, based on the Prophet's (peace and blessings be upon him) saying: "The ruler is the guardian of whoever has no guardian." If there is no Muslim ruler, then his guardian is the director of the Islamic center, and failing that, the imam of the mosque.