It's actually a play on "uruwashii", since "wa" can sometimes be pronounced as "ha" in Japanese. But "uruwashii" actually means "beautiful" in English.

It was something my sisters came up with, and I have had no intention to change it since then, haha.

But lullabies huh? Those would actually keep me awake if I tried to listen to them while wanting to sleep. I've passed out at heavy metal concerts and had the greatest sleeps of my life there, to the amazement of many.