Firstly, she did Not voluntarily stay there. At first she didn't realize she Was in a previous time, and by the time she did she was captured. Tried to return to her time & her husband, and kept getting caught either by the Scots or English. She was pretty lost in that time, and I can feel for her - I know I wouldn't fit in right away, and it would be confusing to say the least.
I do like the show & the book. I'm not surprised it's not on Netflix - it's on W Network & Showcase apparently.
As for lifespan - that's why the women were married so young - lifespan was a "generation" which is 40 years - that's "replacement" for the next generation to be born & able to look after themselves.
