You may want to consider asking your nurse to put the footprints onto a plain white piece of paper if they are uncomfortable with putting the prints right into the book. (mymommystyle.com)
You can easily follow along with just a plain white piece of paper and graphite pencils if you don't have toned paper or charcoal pencils. (arttutor.com)
Tape your design over a blank white piece of paper. (alyssaandcarla.com)