Painted Portrait Vase....El Unico

I purchased this vase about 12 years ago at an auction for I believe $70....The marking on the bottom is a RED DRAGON with the words EL UNICO...It appears to be a hand painted portrait, and is in perfect condition...I found online a similiar vase with the same markings that sold at auction 7 years ago and I contacted the auctioneer, he unfortunately has no records for the piece he sold at that time, so I wrote to the Antiques Road Show and the man in charge of pieces like this had no idea and infact, he was only able to find the same information I had found online...Curious if anyone can tell me about her and what, if any, value she may have!
Sorry about the mark picture, best I could do, I think you can at least make out the Dragon....thanks!