I would take all 3 bunnies to a rabbit savvy vet and let him/her check if Riley really has been neutered, and also if the two babies are really two girls.
If it had been just one baby girl, I would have said, try and bond them when she's about 8 to 10 weeks old. I bonded Luna with my other two, when she was a baby. But the other two had been neutered for almost a year by then. She still gets bullied by them sometimes, although the bonding went ok.
In your situation, because you insisted on having two babies, it is more complicated, as you will have two unneutered bunnies. I have had unneutered sisters who started to fight and had to be separated, before they were old enough to be neutered. Another pair of sisters fell out a few weeks after they had been neutered.
I would keep the babies well away from Riley until they both have been neutered and you've waited another 4 to 6 weeks after that. I don't think it is good for them to see each other, and never put some bunnies together "once a week" and then separate them again. You bond them, and if things go well, they stay together all the time from then on, even for trips to the vet.