I think it's fine until they're 5/6. I used to get in the bath with my mom once in a while. My sister and I took baths together everyday until she was 5/6. I was older only by a year and didn't want her in there with me, but they made me anyway. They also let her scary ass sleep in the bed with me. I didn't want her in there b/c there was less room and she always peed in the bed. She sleept in my bed so much that my matress had more of her piss on it that hers. She also used to sleep in my parent's bed when my dad wasn't there.
She'd sneak in there when he was, but he'd kick her out b/c it was uncomfortable, then my mom would make me let her get in my bed.
I know, i went way off topic. lol Oh well
Since when did having more than one bathroom mean that you're rich?
I've never been in a house that only had one bathroom, and those people aren't rich.
My grandparent's aren't rich and their house has 3 bathrooms. 2/3 is usually the normal number for a house. Apartments are different.
I've also heard that being said about having a basement.