In previous life like ye zi yun, xiao ning also loved nie li and died fighting alongside him. Nie Li accepted her in previous life but she covered face because of a curse which made her ugly and couldn't recognize that both xiao ning are same.
Ye zi yun and xiao ning'er both remembered their previous life but they think it was a dream. Xiao Ning'er expressed her feelings to nie li and what she is dreaming.
Now nie li has accepted her feelings.