MIL and Kids' Bathrooms
Sleek grab bar
For the kids- Wide sink for 2 and open minimalist tiled shelving- 1) enough for bath toys etc; 2) kids can put things away since its open shelving; 3) no worries about water rotting cabinets 4) there's enough space underneath to keep step stools!
Not enough storage space? Consider above toilet.
Hooks instead if towel bars- kids CAN'T use bars. make sure hooks are safe not pointy.