Gu Bailu mentioned Murong Lanyi at this point because she knew that Lady Murong was now dissatisfied with Nan Ningxin.
When someone was dissatisfied, they tended to become suspicious.
Gu Bailu had previously told Lady Murong about Murong Lanyi. While nothing happened afterward, she was sure that Lady Murong remembered their conversation.
And now that Gu Bailu had brought it up again, Lady Murong would recall many other things.
Lady Murong frowned and did recall Gu Bailu's claim that Nan Ningxin killed Murong Lanyi. She suddenly felt that something wasn't right.
Few people in the Murong family knew about the loss of the spirit fruit, and Gu Bailu certainly wasn't one of them.
So, only Lanyi could've told her that.
However… could Ningxin really have killed Lanyi?
"Grandmother, she's lying. I've never seen any spirit fruit. How can I have it?" Nan Ningxin pretended to be bewildered.
