How do I cover up my fireplace for child safety?

Put a fence in front around it

Here are some options: https://www.housebeautiful.com/design-inspiration/home-makeovers/g2260/non-working-fireplace-ideas/?slide=1

Put some doors to make it look a cabinet.

Use a piece of chalkboard, buy some colored chalk, and let the kids draw.

It looks like you have a little indent where the slate board can be set into. If you plan to use the fireplace at a later time, you might want to use "flex shot" or some type of clear caulking. This will, also, seal around so there isn't any drafts and you can, easily peel it off when you decide you want your fireplace back. If you can't find chalkboard, I have heard you can use flat black paint but I haven't tried that.

In order to prevent children from escaping try re-purposing one or two older kitchen cabinet doors and refinish them as close to your current decor as possible !

Find some one inch wood shutters, you can usually get them pretty cheap at the Habitat Restore, clean them well and paint them, you may have to add a strip of wood on the side to make them fit, but I think that would be a good deterrent. for the little ones.

My grandson is one year old. We use pet gates in front of ours.

Get a piece of foam core board, sold to insulate homes, and cut to fit snugly in the opening. Or you could buy the foam core sold for school projects, etc., at stationery stores.

Cover it with a pretty wallpaper, or an attractive poster. Or, if you're artistic, create your own artwork.

Measure just inside the opening of the fireplace, up and down, sides and across both top and bottom. Buy 12 or 16 double headed “scaffolding “ nails.. (yes, they will make removal easy!) , and 2x4’s the total length your measurements added up to, usually sold as 8’ length. Cut that to the topn bottom length and fit the pieces into the opening where you measured, then remeasure the sides n cut them, nailing them in place, into the cement. Start your nails in the boards first for easier nailing. Buy a piece of either 1/2” or 3/4 “ plywood ( not “chip” or flakeboard ) to cover the space, and screw onto the front faceof theframe you just made in the opening. You might want to paint it first...use the “ chalkboard” paint that is available most paint departments, or whatever you want, decorate with a picture, stencils, etc. This will be sturdy and kid proof. Yes, you can do this by yourself ! 😃

Send them to MeeMaw's house....😂

I would hate to cover up that beautiful fireplace, but the baby is much more important. Buy or build a heavy fireplace guard that is attached to the wall in at least two places. Cover the hearth with at least a heavy quilt. If the fireplace is also gas, get the gas company or a plumber to remove the handle. If you leave the handle, a determined toddler can get that handle turned and the gas on. Protect the baby but realize how strong they get to be. Very best wishes!