Thank you for the extra pictures, which show the layout very well. The windowsill location looks great. The spot over the fridge is not going to be bright enough.
While you're in the kitchen doing stuff, take a look where the sun hits inside during the day. There's no substitute for direct visual observation. If the sun does not hit the plant through the window, so the only light it receives is diffused and reflected and mostly second-hand, it's not going to do well. You will see some seasonal variation (winter is a dim dark time). Maybe that upper window on the wall faces due south and has saved the plant thus far... but it does seem to me sort of a miracle that it's gotten so big and survived so long where it is.
Another reason that spot over the fridge might not be so great is if the fridge is putting out warm dry air, which would tend to rise (this would depend on the air circulation) and that is maybe drying it out faster than another location might. Just guessing, but again you can do a little observation to see what's going on.
As a general rule, given that the sun comes from above our heads, especially in late spring and early summer, the higher the location a plant occupies in a room, the less light it will receive. Unless of course it's under a skylight or some translucent surface. Lower down and especially closer to the window, you provide the kind of angle that allows the sun to bathe your plants and keep them going strong.
The babies look charged up and full of life. The soil level is too high in those pots. You need to remove some of the soil so that none of the leaves are buried. The base of the plant should sit on top of the soil, more or less, with just the roots extending underneath. You run a serious risk of rotting them out otherwise. But it's an easy 5-minute job, so why not nip that in the bud. Also, do those plastic containers have holes at the bottom? If not, see if you can make some so the water can exit.
With respect to watering the big plant, try not to leave it bone dry for any extended period. There is no advantage to that. It's a desert plant and it can survive drought incredibly well, but it likes water when the soil goes dry, not a whole lot later. Try poking your finger a couple of inches into the soil on a semi-regular basis until you get a clear sense of when that is (which will of course also depend on the season, the light, the temperature, and everything else).
