I don't think the plan is to link the two time periods, but to provide the separate background stories of Claire and Jamie's respective families, but, I guess, flipping back and forth between the two. While the books have a fair bit of info about Jamie's family/background, there is very little about Claire's. Of course, at least one of Claire's parents must have been able to go through the stones -- it does seem to be an inherited trait, so maybe there will be something on that front at some point, but for sure time travel is not the focus of the story.