The man that Janet and Jennie both see (and who looks at Jennie) is indeed Martin, but formal introductions (and the POV changeover) will not happen just yet, although there will be a few more pre-introduction appearances from Martin. He is not Mary's biological grandson, as his mother (Giselle) was adopted by Mary in 1938 (Giselle was 16 years old), and he moved to the US in 1992. Also, in the next part, Jennie will likely begin her transition (although the part where she becomes James will likely be told from Martin's POV, as he will serve as both a nanny to Tobias and Connie and a lover to Jennie/James). It will also be a while before the mpreg part comes in, and unexpected surprises might come along (might be good or bad, although Martin and Jennie/James will remain together etc).
