The question pertains to Mahayana Buddhism and its doctrinal elements. Let's analyze each statement and determine their validity based on historical and religious understanding:

1. Statement 1: Female deities are benevolent saviors and protectors who embody Buddhist virtues.
   • This statement is correct. In Mahayana Buddhism, there is a significant presence of divine figures, including female deities like Tara, who are venerated as saviors and embody various Buddhist virtues. These female deities often play crucial roles in the protection and guidance of practitioners.
2. Statement 2: In Prajñāpāramitā texts, knowledge is visualized in feminine form, as a deity called Prajñāpāramitā.
   • This is also correct. The Prajñāpāramitā literature, an important part of Mahayana texts, visualizes wisdom as a goddess named Prajñāpāramitā. This deity symbolizes the perfection of transcendent wisdom, a key aspect of Mahayana philosophy.
3. Statement 3: Prajñāpāramitā is described as the source of the omniscience of all the Buddhas and the mother of all the Buddhas.
   • This statement is correct. In Mahayana texts, Prajñāpāramitā is often revered as the 'mother of all Buddhas' because she represents the profound wisdom required to attain enlightenment. She is seen as the origin and sustainer of Buddha's omniscient state.

Since all three statements are confirmed to be accurate, the correct answer is 1, 2 and 3.

Thus, the answer is option: 1, 2 and 3