Since you give her other things besides just layer feed, (oatmeal, celery) The additional food dilutes the amount of calcium intake overall. I know that the additional calcium in LAYER feed is not ideal,,,,,BUT,,,, it takes long term to do a chicken harm. Many peeps feed nothing but one feed,, and if it is Layer, their roosters eat same, as well as their non laying hens. Their chickens are not dropping dead, but live shorter lives than their potential. I choose to give my hens Alflock feed. 2% calcium. REASON; I have layers, and non layers. The non layers, are geriatric hens on social security I only keep my chickens as pets, and they live long lives. 13 was oldest. I do offer Cracked Oyster Shells Free-choice always.This evening I tied the feeder up higher so she couldn't eat it, to avoid her ingesting too much calcium. I left some celery in there to tide her over until oatmeal in the morning
Another little trick in a bind,,, if you are VERY CONCERNED ( I don't really think it is a serious concern) about the calcium intake ,,, Take an equal amount of scratch, and mix it into your layer feed container. You essentially cut the calcium percentage in half. (of total contents of feed bowl.)