Ye Fan did not take the girl to the secret realm first because he didn't want her to meet her mother yet.
The girl had no name. Naming her wasn't related to Ye Fan, as the girl had her own mother, and this matter should be left to Lei Zu.
However, Ye Fan gave the girl a temporary name, Tian Ying, since she had just gained a human body and wasn't yet accustomed to being human. Ye Fan chose to keep her on Earth for the time being, planning to deal with Lu Xiaoman and the others first before returning to resolve this issue.
When Ye Fan reappeared before Mo Xiaoyan with six small crystals, Mo Xiaoyan glared daggers at him.
"Brother-in-law, tell me, where did you go? Do you think I don't know? That girl with a spiritual body was following you; I saw her and didn't mention it. Where did you send her?" Mo Xiaoyan questioned.
Ye Fan replied, "Since you know they're spiritual bodies, you should also know they're essentially servants I've taken in. Where do you think I should send them?"
