Would you do a seperate science with 5th grader and other elemetary students

Hello ladies!  I feel like it has been so long since I have been on the forum.  We were pregnant, then miscarried last May, very early (at 6 weeks), right after I attended the TTD homeschool convention in Atlanta!  Then we found out we were pregnant again a few months later and then moved from Alabama to South Carolina in November of last year!  Since we are due (baby #7) late April, our goal is to finish out the school year, take a bit of a break and start back in July.  So, I am trying to plan as much as I can now, knowing it will be easier to do so before the baby arrives 🙂  I will have a 5th grader and then 3rd grader, 1st grader, 5 year old 3 year old and my daughter with autism who is probably on a 1st grade level but is 8 🙂  So, my oldest son has done all the SCM science except Jack’s insects!  My other school age kiddos have done the following: Learning about Birds with Thornton Burgess with the Thorton Burgess Bird Book and 106 Days of Creation.  We have not done Pond and Stream or Outdoor Secrets with the Companion.  I am assuming my oldest son(5th grader) should do Jack’s Insects and I have no doubt he would love it.  I am struggling with what to do with the other kids since Outdoor Secrets is only recommended through grade 2, but I will have a 3rd grader… so would Pond and Stream be a better choice?  This will be my first year not doing one science with all the kids.  I’m pouting only a little about this.  Any input from you ladies would be much appreciated.  Thank you for taking the time to read and think through this with me.

Regan