If Silver and Maple were both 38 at their deaths, and Shadow was supposed to be 19 I believe, which means that Shadow was born when Maple was 19, and Wolf when Silver was 20.
Okay, plausible. Michael and Maple had a thing going on for a bit, probably not official, and Michael left for Silver before either of them found out she was pregnant.
Which lead to Maple not telling Michael they had a son, and this was probably a period of time that Maple left Silver, until a few years later Maple came back, and most likely left Shadow with Michael while she helped Silver with Wolf. Then I vaguely remember mentioning something about how Maple dissapered once
more for a few years, and if Alec is 7, then that means Wolf was 11 years old. Again, she probably left Alec and Shadow with Michael after two years while she was with Silver and Wolf, periodically coming back to help Michael with the kids.
Sorry, this is me rambling about timelines

But it's actually plausible...hmmmmmmmm