So when did Jacob Jaffe come over? Here are some considerations from a guy who only dabbles in genealogy.
My GM Molly came through Ellis Island in 1921 bringing my 18 year old mother and a 15 year old "son", Reisik Leib Wiezisky. That should have been my then 14 year old aunt Bella, but she arrived in December 1925 at age 19. There was no son Reisik in the immediate family. I expect he was snuck in as a favor to someone. The visa application might have been of interest but I never pursued it.
Have you checked for your GF's arrival in other ports of entry? My father came in through Canada and I found that in Family Search.
I played around in the SM site using search filters: Jaffe/male/birth 1884-88/arrival 1892-99. There are 14 hits. The first one is a Jaffe with given name obliterated. He's an 11 yr old arriving June'95 from Glasgow going to Philadelphia. Seems to be with a mom and 2 younger sibs.
Among the 14 Jaffes I see another spelling for the town. Using the filters without Jaffe but with Suchawola, there's a 9 year old Jankel Weinstein arriving 1898 from Antwerp.
You might try to skim through Bertha's manifest for others from Suchowola. Truly a long shot. Or maybe the gubernia that the town was within.
Hope this helps.