If you've searched everywhere and not found anything about what appears to be a 1980s Longines gold plated ladies quartz watch, I have to ask, where do you expect us to provide answers from? 馃槙
The internet does not contain lots of information about every watch ever made. And unless a model is popular it might contain no information at all.
A very quick google image search using the terms "1980s Longines Gold Plated Ladies Quartz Watch" throws up some close matches for design elements... the fonts and logo match other models, the case back engravings match other models... and sometimes in the game of internet watch detective, that's as close as you can get.
Before buying it, it would be sensible to see what is inside - if it contains a quartz movement that wasn't made in Switzerland, then it's probably not legit.
Beyond that, if you like it, buy it.