Idea to patent

I am so excited about the prayer pocket heart on my dolls. I thought "OH I don't need to patent this idea. It would be a blessing if all dolls had this." Then my sister points out that if Mattel gets a hold of the idea and gets it patented then I can't use it. So, I have started the copywrite in motion. It is disheartening that good things can turn bad in spite of ones intent. I guess it goes to show you must be specific in your intent and protect against the negative. Lawyers...the epitome of positive and negative.