Inheriting properties after un-parenting?

Basically, let's say i have 5 layers, all PNGs, with different sizes.

I have animated Layer 1, and then parented layers 2-5 to Layer 1, so that they move in the same way. I want to now unparent Layers 2-5, but have them keep the same animation properties, so that it looks the same as when they were parented to Layer 1.

I'm not sure how to do this, I think it should be simple, but it's not as simple as, say, creating keyframes in the children at the same marks as the parent, then unparenting.

If anyone has an idea on how to achieve this, it'd be super helpful 🙂