It is possible that they did not want to talk about it, maybe wished to protect you and your siblings from the horrors they experienced. My cousin did 125+ interviews for the USC Shoah Foundation in the 1990's after it was founded by Steven Spielberg in 1994. She found that the people she interviewed rarely shared their experiences with their families, especially their children. Yet, they would talk about it to a stranger. Yes, indeed, there were people who somehow survived it and were able to pick up the pieces of their lives. My cousin's mother, mother's 2 sisters, cousin's father and his brother all did, the emotional scars were lifelong, but they persevered. May I suggest you follow their paper trail as much as you can. Best wishes for successful research! 

Linda Cohen Morzillo
Saratoga Springs, NY