We struggle with this too. Our eldest is MG and significantly 2E, our middle child is 4.4 yrs younger but HG+ and only mildly 2E. The only reason #2 hasn't already blown past her older sister in many regards is that she's not very academically motivated. With reading she has the skill but not the interest to read the same books as her sister (just not interested in The Hunger Games at 7yrs old for example), but their reading aloud has been equal for about a year. She's certainly hot on her sister's heels in many regards. She's starting to regularly try to play her older sisters piano pieces, despite the eldest having had 4yrs more lessons, and her biggest obstacle is hand size/strength.
