Transmitted and non-transmitted alleles

I’ve been revisiting the lecture on “Estimating Intergenerational Transmission” by Jared Balbona. I am confused about the influence of paternal and maternal Familial Environment (FE; Fp and Fm). Based on Jared’s example, do we consider these to be how often the grandparents’ read to the parents?

Also, if we would only like to look at mother-child influence, could you kindly recommend how we could extract the maternal transmitted and non-transmitted alleles, given that plink --tucc only extracts this information for the whole family trio unit?

Thank you so much!