Here are the ages:
6 month old...just tagging along

2yo and 4 yo (3 and 5 in the summer)....will be starting Little Hands soon. Is it OK for 5 yo to use Little Hands for K or should she be in Little Hearts?
6yo boy...not reading yet. He will be 7 in May and will be 2nd grade next year. It looks like to me he would place best in Little Hearts, but, is that OK if he will be 7 (2nd grade) using it?
9yo girl. Will be 10 in Jan. I am finishing up MFW Adventures for her 3rd grade year. Would it be too much of a repeat for her to use Bigger Hearts for 4th grade? And, if we did use Bigger Hearts, would I need to use the extension pack?
We will most likely be starting Little Hands in the next month, but the older children would probably not be starting a new program until the summer, possibly the fall.
Thank you for your help!!!