In the event that a boy was raised by his stepmother and she raised him since he was about 6 years old, is she considered the boy's mother in front of Allah's eyes? i.e. does she get the same rights as the mother who gave birth?

A Muslim must be grateful to those who do him favors. Such virtuous woman who treated, cared about and raised her husband's son like her own son is entitled to all rights of respect and self-esteem.
On the other hand, being dutiful and kind toward this woman is the same as being so toward the father. The Prophet (peace and blessings be upon him and his family) said, "He who does not thank people, does not thank Allah Almighty."