In Jack's introductory montage, he's shown rowing with a particularly grim expression on his face. You might expect that he's just exerting himself, but in a later episode he reveals that rowing helps him cope when his PTSD flares up.
In Season 1, Hanin Ali is shown to have adolescent children but is portrayed by Dina Shihabi, who was in her mid-to-late twenties when she filmed the role. This leads to the implication that Hanin was a child bride, which is strongly implied later in-universe when Suleiman tells the "romantic" story of how he met her- by buying her from her father. It is further implied that the reason Hanin flees from Suleiman with their daughters is to spare their eldest daughter the same fate.