Hi, OldGuy43! First, my little story of introductions:
When we introduced Romy and Michele to the Runners, we set up a little fenced in area, about four by three, adjacent to the Runners' pen. Now, this being New England in late fall, and Amiga being Amiga-the-pamperer-of-ducks, the Runners were spending their nights in the basement pen. So we did not have to build anything predator-proof. I digress a little tiny bit.
So we brought R&M home in the late afternoon, just before night-night time. We put them in their own little room, and then brought the flock in for the night. That way, they could see each other, and no one had to defend turf or establish their legitimacy.
Worked fine. Zwei was first to go over and meet the new girls. There was some posturing, a lot of chattering, and everyone went to sleep.
Over the next several days, we gave them more and more supervised time together, first on opposite sides of a fence, then face to face. There was more posturing, and a little poking. This went back and forth for a while, but by the second day, the Runners refused to go anywhere without the Buffs.
It is now three months later and the flock has completely blended. It's been this way for about a month, I'd say.
That's what we did. I would reckon that with littles and an adult, there are some big differences. But the principle would seem to be the same - give them time side by side, separated by a fence. For the Quakerettes, I would not leave them with LD until they are at least almost as tall as she is, and only after repeated, closely monitored face time. I feel they need to be big enough to push back hard, if necessary.