Good job!
I would certainly pot the ones in water now; I would use a smaller pot than the previous two, though.
It looks like the mix you used on the older two is somewhat dense; I would not use that again. A light African violet mix works for H. bella (or lanceolata v. bella if one prefers that taxonomy). Alternately, you could lighten that mix with perlite.
I do feed them right through spring to fall, then give them a pretty cool and pretty dry winter rest.
If your window does not get much sun be sure to keep them very close to the glass. Hanging in the window would be better than standing below it. You don't say where you are, but if you get super cold in winter you might have to pull them back then.
I always propagate a few new ones each year and give a few away to friends. They can give you back some cuttings if you loose yours…
