Electric shower? Doesn't that hurt?
I assume you mean electrically heated shower?
Anyway, that's typical. High current stuff has it's own breaker (dual breakers in one package for 240/480v). Lights are usually all on one except maybe if you have two floors. Electrical outlets are typically ganged 10-15 receptacles on one breaker. I wouldn't mind rewiring my house so that every room has a seperate breaker for receptacles...