I think I have a broken jersey giant.

[matt1898]

The slowest growing of my 3 jerseys has started laying several weeks ago.
I keep getting these bantam eggs. Lol.

 

[howfunkyisurchicken]

Aw, its cute

They'll get bigger. I've gotten jelly bean sized eggs from some of my bantams.

 

[LukeandAli]

I had a full grown JG who gave me tiny eggs (a little smaller than a ping pong ball) for a couple weeks after we bought her before she started producing normal eggs. I thought sure it was one of my chicks laying early (16 weeks), but, I "caught her in the act" one day. It was a bit of a surprise!

Give her some time and she should be putting out big eggs like her sisters.