Wrist Cuff

So my daughter has a problem. She sucks her wrist. It doesn't sound that bad just saying it like that. And it has it's good points. She has never taken a binky and I love that. One less thing to remember to bring smewhere, no waking up at night to stick it back in her mouth and no weening from it. But she SUCKS her wrist. Gives herself hickeys. Right now her wrist is purple, swollen and since the teeth have come in she is starting to get teeth marks in her wrist now. It is really bad. So I decided to make a cuff to cover it up. I made this a few weeks ago and it worked pretty well. She tried to get around it but for the most part she just decided it wasn't worth the trouble. I would take it off for sleep time only. The snap has since broken off so I need to make another one. Does anyone have any tips on how to use snaps well? I doubled up fabric and used fusing which helped but it still didn't last all that long. Send me a comment if you have used snaps succesfully before.