I've found a possible connection to the Global Tree through one of Geoffrey Arend's great granduncles, Bernard Arend. However, it's going to be in the range of 45 to 50 steps, so let's not stop working on Christina's tree.
There have also been a good number of branches reaching out from Christina's stepfather's ancestor, Morris Stept. As Steven mentioned, the proximity to AJ's family in Pittsburgh in that part of the 20th century increases the likelihood that we'll be able to connect to the Global Tree there. There are lots of children and spouses to choose from, so anyone who wants to explore this possibility can just pick a profile and keep working out from there!
Chris Hoyt also mentioned a tree she found for Jackie Raymond (Christina's mother). Does anyone want to take a look at it and check for sources and accuracy?
Thank you all for your work on this!