Hi,
I have that configuration right now, for about 2 months. Mom(Black Fury ca. 4 years) with older daughter (Red Shrew, 1year, just kindled her first litter) and now a younger sister(gray), 6 months, too.
The Red was with the Black since she was born and was a great big sister for 2 litters. That was no problem at all, some humping by the older doe from time to time, but otherwise a harmony you can only hope for.
The last one was seperated for a month with the growouts, reintroducing her was some stress, some tufts of fur, lots of sitting in a corner, but I think it works out. Would have been better to never seperate her from mom and big sister, and it didn't help that my shrew was pregnant. Still have a nervous eye on the scene, hope I don't have to take the grey out.
But they need a bigger hutch soon. I added an extra big box, imho it's important that they can disappear out of sight, and that each one has its own private resting spot.
I'm doing this because it's so much easier to just tend 1 hutch instead of 3, also all rabbits get more garden time when I don't have te seperate them. And I like the interaction of bunnies, they too, I think.
But it sure depends on the individual rabbits, there is no guarantee that it will work.