First of all you need a good set of pictures. A good set means quality and different angles. Preferably from around the age she performed. A much older photo can live in a different pimeyes dimension. Same goes if she had a totally other look in those days. Sometimes pimeyes sees right through it, but sometimes that side of her can be hard to discover with pimeyes.
Also, pimeyes is relatively new. If she was active on smaller sites that are no longer active, it can also mean pimeyes just does not know her (yet). Other than that, you can do a few tricks, but those are a bit harder to guide you through.
And sometimes you need to use other sources besides pimeyes to find things. Pimeyes is great, but it also has it's limits. Especially if you want to search beyond the results it gives. (and believe me, the best results from pimeyes, are not always the "best" results).
I'd be happy to assist you and see if I can find her for you. (if you want, you can direct message me 1 or 2 pictures, I will treat them discretely. Any result I will direct message back to you)