I didn't really think there would be an issue. The older one might chase the babies occasionally, but I doubt if any harm will come to them. It's just been so long since I've had fry that I wasn't 100% sure it was safe.
The only way the two month old could eat them is if they were so small that they could fit in its mouth. From what I can see the two month old looks like it is large enough that it would be safe in the tank with the adult Platy.