The mother of infant Fan Zixuan kisses her baby after the 11-month-old was discharged from Beijing Children's Hospital last Wednesday.
The baby, from Shandong province, was treated after 16 needles had been inserted into her body.
She underwent surgery on Oct 28.
Police had focused on Liu Hongyun, Fan Zixuan's aunt, as a suspect. Liu died on Sept 24 after taking poison.