Thanks for the mittens pattern; will keep a ‘Chicken Vest’ in the back of my brain, LOL!
Looked around a little - thinking something like this .... button front, can’t be a pullover. Looks like room for maybe 6 egg pockets, potentially 8. Sizes are: 2-3 (3-4, 4-5) so that’s good.
https://www.purlsoho.com/create/2012/06/24/whits-knits-classic-crocheted-vest-for-little-kids/
I’m going to keep looking around.