My husband is from Tinian orginally, and we now reside in Massachusetts. His mother was Francisca De Leon Guerrero (still using the "De") and De Leon Guerrero is the "middle name" of all of her children, including my husband. She was born in the early 1900's, probably around 1924, and died a few years ago on Tinian. Her mother was Regina De Leon Guerrero. Regina DLG married a Korean in the Mariana Islands, Sek Man Yu (but I think the Chamorros called him Jose). That's all we know. My husband doesn't know where his mother or grandmother were born, although his first guess was Guam. His maternal grandmother died when his mother was only 4 years old, and then the Pangalinan family of Saipan raised her (maternal cousins).
Have you come across Regina De Leon Guerrero or Francisca De Leon Guerreo (married Jesus Matsumoto)? I would be very interested in any information about the De Leon Guerrero family that you can offer. I did read the information on the Guam history Buff website and found it very interesting.