For pieces with this iconography, see David Howard, The Choice of the Private Trader – The Private Market in Chinese Export Porcelain illustrated from the Hodroff Collection (pp. 283-284).
Additonal informations :
Hsi Wang Mu, Queen Mother of the West, Royal Lady of the West, is a fabulous being reputed to dwell in a palace on the K’un-lun Mountains, where she presides over the hosts of the genii and guards the peaches of immortality.