The Ilowite Family Tree
Children:

Aaron and his wife Martha lived in or near Odobesti, Romania. We don't know a whole lot about their lives there but we do know they had six sons who immigrated to the United States in the early 1900s. We don't think they had any other children who did not come here (although we don't know this for certain - Steven Crayne says that Arthur told him there was another brother who died shortly after birth), and we also don’t know for sure why the sons came. However, it’s probably a safe assumption that it was for the common reasons - the lure of the chance for greater freedom, economic opportunity, and a better life, as well as escaping the oppression of Jews that was prevalent in eastern Europe at the time. Aaron and Martha did eventually follow their sons to America at some point in the early 1920s and briefly lived with their son Irving's family. We do not at present know exactly when they passed away or where they're interred.
According to Irving, Aaron and his relatives earned a living doing work that involved mathematics, since Jews were in general much better educated than the general population - and it was fairly common in most of Europe that when someone was in need of such skills they would "get the Jew". Examples of these kinds of tasks would be land surveying, mortgages and loan amortizations, as well as seasonal work relating to the wine industry such as calculating harvest yields (Odobesti has a long history as a wine producing area).
In addition (no pun intended!) to this, mathematical talent appears to run strongly in the Ilowite family, as borne out by the many descendants who have excelled in the sciences and other professions that require it.
Here’s a description of the Odobesti region from a website:
Odobesti Wine-Growing Area
There are wineries at Sarba, Baciul Domnesc,
Cazaclii Jaristea- with systematical grapevine plantations at Pauleni,
Varsatura and Scanteia- Bolotesti.
Location and history: The
wine-growing region is situated in the middle of the Vrancea county, a massive
wine growing territory between the rivers Putna and Milcov. The wine-growing
territory has a surface of about 6000 ha. The first documentary evidence dates
from the reign of Eustratie Dabija (1661).
Soil and climate conditions: At
Odobesti stands out the dominance of the continental character of the thermal
regime. The annual average temperature is 9.6ºC.
Range of wines: White table wines: Galbena de
Odobesti , Feteasca Regala, Red wines: Babeasca Neagra, Feteasca Neagra.
High
quality white wines:
Feteasca Alba, Italian Resling, Sauvignon and Muscat Ottonel.
High quality red wines: Cabernet
Sauvignon, Feteasca Neagra, Merlot.
Representative wines: Galbena
de Odobesti, Feteasca Alba.
Rick recalls that Irving once said the original family name was something like Ilyici (pronounced eel-yich-ee), however we’re not very sure that’s the correct spelling or pronunciation. It also seems possible that the name is what is known as a “patronymic” since a “yich” or “vich” sound can mean “son of”, so in this case it might mean “son of Ilya” with there being yet another surname we don’t know about.