Are you talking about breaking pitches and taping a line around them?
2 points!
Draw a center line with dots of sketch in a line with an ink pin first.
Determine which seams she will use for the pitch. If she is small, she will probably use a two seam grip. The photos here show stripping a ball with a four seam grip. The line will be drawn the opposite for two seams. If you go to my facebook page and look in my photos, "softball" photos, you will see a technique I use with a drink cup. This link is for the drop ball and fixing fastball problems. If you click on the photos there is dialogue. Click on the word "Facebook"
When I tape a ball, I do it across the four seams. Take a ball and turn the seams so you can see a C or a backward C (doesn't matter which). You could also say turn the horseshoe on its side. Now tape from top to bottom, all the way around the center.
I use electrical tape, which holds up pretty well. The challenge is getting the tape to match up when you go all the way around. You may have to pull the tape off and re-set it before rubbing it down permanently. It may not be perfect but it doesn't have to be. As long as it's close enough.