i'm guessing her name could be taken as contraction for the Chinese diminutive "Little Oily Mouth" so often used in JAMES CLAVELL's "Asian Saga" novels?
https://books.google.com/books?id=WK2G6L5Fje4C&pg=PA593&lpg=PA593&dq=Little+Oily+Mouth&source=bl&ots=6Bn9AHlLPj&sig=copL0Nf_vvNAkMyMsztk-xyEkSQ&hl=en&sa=X&ei=KBXJVJSOIorUoATiqoD4Bg&ved=0CCAQ6AEwAA#v=onepage&q=Little%20Oily%20Mouth&f=false
https://books.google.com/books?id=WK2G6L5Fje4C&pg=PA593&lpg=PA593&dq=Little+Oily+Mouth&source=bl&ots=6Bn9AHlLPj&sig=copL0Nf_vvNAkMyMsztk-xyEkSQ&hl=en&sa=X&ei=KBXJVJSOIorUoATiqoD4Bg&ved=0CCAQ6AEwAA#v=onepage&q=Little%20Oily%20Mouth&f=false