Find our distant family

Hi everyone I'm new to the forum I'm just looking for help locating some distant family who lived in the gaucin area I dont have much details but my great grandmother and her family were from gaucin  before she moved to England after meeting my great grandfather and she sadly never returned to spain her daughter my great grandmother tried to trace family without success back in 2012 when she visited gaucin this being the only time she has left the uk to see her mother's home town she is now losing her memory with dementia and I would like to do all I can to help her find some answers  before it's too late for her and us I dont have much information but I do have a letter sent from my great great grandmother to my great grandmother with a name on the bottom could anyone point me in the right direction for help thanks