Hmmm.... I played through TWICE now, on Sisterly... and NEVER got ANY time with youngest girl, always the middle girl and oldest girl, and never got any time with the Mom, save one hiking scene deepish in the game.
I admit, I always chose to help and comfort the older sisters, is that it? Do I have to perhaps initially keep them at arms length, do NOT help them or comfort them, to instead go off and grow closer to the youngest and the mom?