She has a great tutorial. I used the dimensions and it really helped me understand how I might put one together. The customer had a similar one and wanted it like her old one. Instead of using a removable foam pad I used extra loft batting and doubled it. I sewed it into the mat. I also used fleece for the blanket and put a binding around it. To finish off the blanket I embroidered the name of the little girl on it. If I make any more I would make the strap a little different.
I would recommend this tutorial. The first mat took me about 3 hours but i cut that time in half by the third mat.