Divine mother is the form of all the Varnas. As per Vedas, there are four Varnas.
It is said like this in Purusha Sooktha
Braahmanasya mukhamaaseeth baahu raajanyah kruthah
Urootadasya yadvysyah padhbyaagm shoodro ajaayate
Brahmanas came from the face of Paramatma. Kshatriyas came from his arms. Vysya came from his thighs and Shudras came from his feet.
The one who teaches about Brahman (Paramatma) is Brahmana. He mainly uses the faculties of intellect and speech to spread the knowledge about Paramatma. He teaches dharma (as set of rules to obey in order to prosper). He has Sattva Guna for most of the time. He exhibits intellectual tendencies. The one who establishes dharma preached by Brahmins is kshatriya. He uses the power of his strong arms to ward off anti-social elements and acts as the protector/savior of the Kshetra (kingdom). He is always ready to sacrifice his life, if need be, to protect dharma. These are the warrior class. They have a mix of Satva and Rajo Guna. He exhibits intellectual and social tendencies. The one who learns the business secrets of various trades and brings prosperity to the society created by a kshatriya is called vysya. like thighs in the body, there is an element of secrecy is his demeanor. He protects these trade secrets and passes on to the next generations. They have a mix of Satva, Rajas and Tamo Guna. He exhibits social and physical (related to physical body) tendencies. A prosperous society has to be well fed and served. It requires laborer, farmers etc. who use their strength and stamina to serve the society. They are shudras. They are always inclined towards carnal pleasures. They have Tamo Guna for most of the time. They exhibit physical tendencies (related to physical body).
All of us are shudras by birth. It is because children lack the discretion of good and bad, right and wrong. After taking school and college studies, few children transform into a Brahmana, kshatriya or a shudra based on their karma and guna. These are called Dwija. They wear the sacred thread on their torso.
It is said like this Bhagavadgita
Chaaturvarnam mayaashrushtam guna karma vibhaagashah
I created the four varnas. Beings are classified into one of these based on their guna and karma.
It is said like this in Brihadaaranyakopanishath
In the beginning of the creation, there is only Paramatma. That is the dazzling light spread everywhere. That is Brahmana. Kshatriya or others are not yet created by then. Then Brahma thought, the brahmanas I created need protection. Then he created kshatriyas. Devatas like Indra, Soma, Varuna, Megha, Rudra and Yama are Kshatriyas. He assigned the duty of protecting Brahmanas to Kshatriyas. Even after that Brahma thought there is something lacking. He thought Brahmanas are learning about me, Kshatriyas are protecting them, but these people need prosperity to sustain. Then he created Vysyas. Their duty is to bring prosperity to the society. Then he created 8 Vasuvus, 11 Rudras, 12 Adityas, 13 Vishwedevatas, 49 Maruth Ganas and 93 Deva vysyas. Even after that Brahma thought there is something lacking. Then he created Shudras to feed and serve people of all these three varnas. Pooshudu is a Shudra. The earth is Poosha. She is feeding everyone.
Explanation
1. The one with Brahma Tejas is a Brahmana. He is in quest of truth. He is always yearning to know the Brahman (Paramatma). His face has the flow of Brahman.
2. The one who came to protect Brahmans is called Kshatriya. He duty is to protect. Hence, he has strong arms. So, he is born from the arms of Brahma.
3. The one who brings prosperity to the society is Vysya. Thighs are a secret place in the body. Not shown to others. Similarly, Vysya protects the wealth secrets and passes them on to next generations. So, he is born from thighs of Paramatma.
4. The one who feeds and serves all the above three varnas is a shoodra. He uses his strength and stamina to cultivate land, build houses etc. So, he came from Paramatma's feet.