When do I know my leaf lettuce is ready to eat

[Guest guest]

I forgot to ask this question when I first posted about growing this on my

window sill.

I got the plant from the cooking class last week. I replanted it in the coco

coir and it's on my window sill getting the sun and it's all perky but I have no

idea when (or even how) I harvest this. Do I wait until the leaves are ALL OVER

THE PLACE, or do I snip pieces here or there.

I have no clue. I water it every day, it seems to be doing fine. But is it going

to get taller? And how long does this take? Thanks much

Melody