I think you may be right. Three of Dewalt and Catherine's children were baptized in Pennsylvania and the sponsors were: Conrad Defenbach and Magdalena (Riffle), Jacob Boniwitz and Rosina, Jacob Franck and Saleme. I've always felt that at least one of the sponsors is a relative of Catherine's.
I don't have much information on John Wesley Halfhill, but know at least two descendants of Jacob's who may be able to help you. I will ask one of them to respond to your message.
Thanks for your help,