LeAnna,
I agree that it wouldn't be a good fit for Audrey to head into Bigger Hearts at 6.5. I was thinking Audrey would pretty much be 6 by the time she was beginning Beyond, thinking she was 5.5 now.
It is not any problem for her to do A Reason for Writing A along with Beyond, in place of the poetry copywork. We'll be doing the same thing with our own little guy this upcoming year. I'd just omit the poetry copywork for her altogether.
I also wouldn't begin the spelling lessons with her until she is close to finishing The Reading Lesson.
It is definitely worthwhile to work to keep two kiddos that are so close together in age together if at all possible. I do think with just a bit of tweaking in the early years that you could keep these two kiddos together for the long haul. So, my advice below is going to be leading in that direction.
At the beginning of your next year, it would be a good idea to begin at half-speed with Beyond for the first 2-8 weeks and even longer if this is a good fit. This will give you time to ease into the program and also give Audrey a bit more time to mature at the beginning of Beyond.
Next, I would move into Beyond at full-speed 4 days a week when the girls seem ready. This will be a good pace to keep the girls moving forward, yet will leave you time to explore special interests on Fridays. Singapore math is advanced, so you won't be falling behind by following this schedule. A little additional time to mature in the math area is actually a good thing. Our third son in 4th grade this year is just now starting 4A. He's very mathy and tests in the 99 percentile in math every year on the Iowa Basics, yet this is a perfect level for him in Singapore.
Since Olivia is on the young side of Beyond too, this would be fine for her as well. There's no hurry to get to the upper levels of Singapore math too soon.
Then, the following year you would take the first 10-13 weeks at 4 days a week to finish Beyond. Next, you'd head into Bigger Hearts at 4 days a week. By this time Audrey would be 7 and Olivia would be 8. You wouldn't worry about Audrey doing cursive in Bigger, as she'd be doing the copywork of poetry in Bigger Hearts instead and would just do the cursive the next year with Preparing instead. You might have to modify some of the copywork for Audrey within Bigger for the first while too, but you'll know better when you get there.
If at that point you still felt Audrey needed more time to mature, then you could always have her bump back and join your upcoming little one who by this time would most likely be in LHFHG.
I'd love to hear your thoughts on this if you get a chance.
Blessings,
Carrie
