With two night shifts she already has more than 50% covered... I know many who split it this way: the day shift worker takes the kids out in the morning, early afternoon the night shift worker picks them up from daycare. And on weekends, the grandparents get a turn :)
Just look at this example alone, there are surely others as well.
You have little equity but the situation with your parents and sister is something super important that many don’t have. Your wife has a secure job and can therefore work more when things get tight or if you want to afford more. Or you shorten the loan term through special repayments, etc. In my circle, the women happily went back to work, often also shift work.
If you discuss it with your parents like this, they will surely cooperate and help you much more, plus it’s great for the kids to experience grandparents.
And just like that you regain financial security.
We built many years ago, and it was exactly the same. I worked shifts or was around during the day, my wife worked various shifts and the kids liked being with the grandparents. The parents help you with that and you help them when they need it. Unfortunately, that is disappearing nowadays but that’s how we built. Without that, nothing would’ve worked. That fits together, you just mustn’t get silly notions in your head, like 40-hour work weeks or similar stuff. Live a normal life and then it works without real sacrifice.
Nice house, obviously no renovation backlog. Put aside photovoltaic income for repairs or so... all good.
Regarding work and shifts. Yes, we would also do it with night shifts and yes, the grandparents, so our parents, are always really happy. I also have a sister nearby. So I don’t see a problem ^^
I’m telling you, you’re lucky!
Regarding the bathroom:
I would do the wall tiles above the platform as built-in cabinets in shabby style: build stable doors yourself, then stain and paint them and wipe them to look old, then cover the wall with it. Narrow wooden board on the platform, old chair in front, throw in towels, anchor here, seashell glass there... sink on wooden board, get rid of the mirrored cabinet, put an Ikea mirror in...
Something like that and your place is done; this bathroom is a one-of-a-kind, your self-designed bathroom.
Yes, we definitely have to fix up the bathroom like that to make the best of it ^^
When the time comes, I’ll read your post again and see what would be possible
Believe me, most people would gladly trade this problem. There are countless possibilities, especially for little money and nice results. And... it’s not necessarily urgent. You can but don’t have to do it right away.