Face detection of similar faces

[pabera]

Similar to this request #13311, I have a 2 siblings in my library. They are a couple of years apart. They looked very similar as babies of course. And Immich doesn't recognize them separately.

Immich has grouped both their faces under one, 10k+ photos. Is there a way I can get them separated?
I started to reassign them manually (would take a bit of time), but I notice that newly added photos are still recognized wrongly.

How does it work under the hood? If I am able to reassign more photos manually, would Immich start to be able to distinguish them at some point? I just want to avoid that I put time into this and in the end, the ML has learned the wrong thing.

Since both kids have a separate age, maybe there is a way to ask the ML to learn until a specific date (until the second kid is born)