Yes, that should work really well. In a week or two the tiny ones will have enough size in case they accidentally get jumped or stepped on by the Buff Orpington. The Buff will also be really happy in that situation:)
It looks like they are way too tiny right now. The size difference is huge. If you are going to put them with her you need to put up some wire, a piece of hardware cloth or something so you can observe them, maybe for a week or so.
Your Buff Orpington won’t feel alone and you can see if they...