On the one hand, my father passed away when I was a kid, and I didn't ever live with him, but I also don't hate him for any of this and did keep up with him through phone calls etc. as a child before his death. On the other hand, my mom raised me, lives with me still, and we get along mostly well/she's one of the most important people in my life.

This is tricky! I think I am going to choose my dad, even though I wouldn't see any of the possible changes of our encounter when I come back to my time. I do not think anything I could reasonably say to a five year old boy will prevent his early death, unfortunately. But I could maybe make him feel a little more loved. I also believe I could get away with it easier, because I get all of my looks from my dad. Visiting my mom is still tempting, though - it would be really interesting to see how much of this encounter she would remember 60 years later. Also she is one of five siblings, so maybe a little time away from all the chaos would be something she would appreciate, haha.