Hi Bharper, and welcome to the HOD Board!

The Emerging Reader's Set is one of my favorite all-time things to do with my dc. I am doing it for the last time with my third ds coming up this school year, and I honestly cannot wait!

You probably know this, but the Emerging Reader's Set is scheduled out very nicely in the Appendix of Beyond Little Hearts, and it has super oral comprehension questions that you ask your dc (which do a lovely job of teaching them better reading comprehension and beginning oral narration skills

).
I can see what you are saying here - how do you share the books? You make good sense with your point that stagger starting your dc would make sharing that much easier. I have a few ideas on this.
Option 1: Have your 2nd grader begin the Emerging Reader's Set first. After that child finishes the Bible, have your first grader begin it.
Option 2: Have your 1st grader begin using "The Early Reader's Bible" and have your 2nd grader begin using "The Beginner's Bible." This would require you to get both Bibles, but it may be worth it to start them both reading right away.
Either option would work well! I am excited for you to begin Beyond Little Hearts. We had many favorites in Beyond, but a few of our most beloved memories are with reading "American Pioneers and Patriots" as well as reading and discussing the "Morning Bells" devotional. HTH, and I look forward to getting to know you here!
In Christ,
Julie