It is not a cross-cultural or social phenomenon for women to respectively raise versus nurture their daughters and sons.
This trend in parenting is most often seen amongst lower economic and disenfranchised populations.
The reason being is greatly due to high volumes of single-parent homes and the frustration as well as effeminisation of the males of these groups who find it difficult to thrive or provide a soundly stable financial existence for themselves and for their families.
As such, women of these demographics feel it necessary to raise their daughters to be self-sufficient and self-preserving, while they nurture their sons by displacing their desire for emotional bonding with a male.
In other words, many women direct towards their sons the energy and efforts of love and nurture they would normally carry for an adult male partner.
This is especially true for single mothers who have been scorned. While projection of sexual feelings are not present, the mother nevertheless prizes her son as being the man in her life.
Explains a lot.