I don't have any new advice to add, but I am right there with you! My dd did K at 3, first at 4, and is now doing second at 5.5. I managed to buy a little time in the middle there by going sideways. I just don't tell anyone. She still goes to the K class at church where her friends are. My 2 yr old is already working at least a year ahead in the developmental milestones and well into preK academics on his own. He's more vocal than his sister, so I'm sure we'll get into some sticky situations with him!

When we did A, my oldest was 9 and using Core D. The one in A was 6, and I had a 3 yr old. The baby was born near the end of the year. We just finished A the second time with my 5 yr old while I had a toddler and sister in C, brother in F.

We love Sonlight here! I have used every Core from P4/5 to F. A is a great introduction to time periods and cultures, and it has a missionary focus. B starts an in-depth study of Ancient world history So, you can't compare A with STOW as apples to apples. That being said, Core A is great for the ages of your kids. I can't tell you what will work for you but we have learned and the kids have retained so much with Sonlight. Sonlight uses STOW with cores G and H, so those do come into play.