She is the Beili courtesan he encountered there, playing guquin, while Sikong Chanfeng found himself capable of follow that specific music playing a leaf

Feng Qiu Yu / Feng Ling Luo is Sikong Chang Feng's wife. 

 Anthony Tumiwa:

i just remembered i created this topic after got a notification someone replied, haha.

actually i got the answer long time ago.

so the answer for my own question is ... Luo Shuiqing 

like @HaruPA said, she is an original character of the novel, not make an appearance in drama.
perhaps the two met after the event of Dashing Youth.
She passed away while giving birth to Sikong Qianluo.

i think the drama producer change this character to Feng Qiuyu is because to add extra "Romance" element to drama version, because Luo Shuiqing had not met Sikong Changfeng yet in dashing youth timeline?.

@Anthony Tumiwa Not really Feng Qiuyu and Luo Shuiqing are actually the same person 

Acc to novel (I have read all the Novels Trilogy of  ZMN's Jianghu series)

so ,Qianluo's mother have changed her name 3 times

1) when she was still a Nanjue princess she was called Feng LingJue (i.e her real name)

~2) In Tianqi city , to hide her Royal identity she changed it to Feng Qiuyu

~3) Later, after marrying SCF; she was known as Luo shuiqing

 Anthony Tumiwa:

@Scarlet 
oh... Baidu page doesnt have that information.

When she lived in Tianqi City, was she a courtesan like in the drama adaptation? Is she a spy or something? Also, does the name 'Feng Ling Luo' exist in the novel as well?

@Anthony Tumiwa The drama version actually follows the novel for feng Qiuyu , except they didn't reveal her identity as Nanjue princess (which makes Qianluo also a part of Nanjue Royal family)

 she herself said she was a former Nanjue princess in the Novel of Dy and also Sikong Changfeng himself said in the Novel that she insisted on changing her name

Lines from the Novel:

"The spear technique I'm about to use is one I recently created. I've been forgetting to tell Baili Dongjun that I'm now married, and my wife, even though she insisted on changing her name to Luo after entering Xueyue City because she thought it sounded better. I also have a daughter. She has a very beautiful name, Sikong Qianluo. I've missed her a lot these past few months, so I created a new spear technique called Qianluo. Watch closely."

The "Three Heroes of the Wind and Dust" suddenly sprang up and pounced on Sikong Changfeng.

and about Feng Ling Luo........uhm I don't seem to remember this name being mentioned in either of the Novels I have read.

(ps. Luo shui qing name was repeatedly mentioned in TBOY novel as SCF's wife & SQL's mother)

many novel readers in china also have come to this conclusion that SQL's mother has changed her name 3 times