Ruoran had indeed a good comprehension. After Fan taught her the breathing exercises, she was able to master them right away. However, since her body was weak and she had only just begun to practice cultivation, she could only maintain the cross-legged breathing exercise for two hours before she started to falter.
Fan didn't insist on Ruoran continuing the exercises forcefully. For her, letting things take their natural course was best at this time. This was a period to lay the foundation of cultivation. Being too demanding could lead to the opposite of the desired result.
After making sure Ruoran was comfortably lying down, Fan refrained from any further intimate gestures.
If he were to deflower Ruoran now, her future path of cultivation would become even more arduous. The only thing to do was to wait until Ruoran had reached the Fifth Level of Qi Cultivation, and then it might be possible to find a Cultivation Technique to practice Dual Cultivation.