This may sound bad to some but here goes . . . .. the showers have a 2" lip around the bottom. In desparate times, you could block the drain (after cleaning the shower) to fill up that small area with water. It's not much but would work if you had no other way. The sinks are a bit small but it's possible to give the baby a sponge bath right on the sink.
Signed . . mother of 4