Our fourth grandchild is due to arrive later this summer; once he gets home, his mama will keep him close to her in a co-sleeper that sits next to her side of the bed. It’s hard to find sheets for such a small mattress, so I make them for her.

Here’s what a co-sleeper mattress looks like:

And here’s how to make a sheet for it:

Fold your fabric in half, right sides together. Then place the co-sleeper on the fabric and pin around the entire mattress. I used one yard of 60″-wide knit fabric, which worked perfectly for the 20″ X 33″ co-sleeper mattress. Sew along the path of pins, removing them as you go, until you come back to where you began. Back-stitch a little ways before you remove the sheet from the machine. Then trim around the stitching, leaving an approximate 1/4″ seam allowance:

Using a zig-zag stitch, go back along the raw edge and stitch to finish the edge:

You may be able to tell that I used a narrow zig-zag for the initial stitching as well as on the raw edges. That’s because I used a knit fabric and the zig-zag makes for a more flexible seam. But if you’re making this out of a non-knit fabric, just use straight stitching for the seam and zig-zag for the raw edges.

So what you should have now is a big rectangle of two layers sewn together that you can’t open because we didn’t leave a space to turn it. No worries, that’s how we want it. Measure in 6″ from all edges and mark with pins:

Your project should look like this:

Now, on only the top layer of fabric, cut out a rough oval just inside the pins:

Your sheet should look like this:

Note that mine isn’t a perfect oval. Yours doesn’t have to be, either  🙂  Now turn the sheet right side out, and press the oval’s edge after folding over a half-inch:

Take a roll of elastic (I used 1/2″ wide, but 3/8″ or 1/4″ would work as well), place the end of it inside the little hem you just made, and start stitching with a zig-zag stitch, stopping to stretch the elastic as you go along:

It’s hard to see, but the elastic is under the folded-over fabric here. Just keep stretching and sewing, a few inches at a time, until you go all the way around the oval. Back-stitch when you finish. Then turn the sheet right side out and put it on the co-sleeper mattress. Here’s how the back should look:

And here’s the front:

I bought the elastic at Hobby Lobby, where a 4.5 yard roll of 1/2″ elastic from their Sew-ology line costs $1.99; sometimes all of their Sew-ology notions are half-price, so that’s a pretty good deal for a grandma who’s been making crib sheets, little girls’ dresses with elastic necks and sleeves, etc.

Eagle-eyed readers might notice some children’s fabrics in the upper-left corner of the photo. Yes, there is a baby quilt in the works for our new little grandson. Stay tuned!