Oath on Allah while touching someone or something like a human being or the Quran’ul-karim mushaf?

As-salamu ‘alaikum, I have a question regarding oath. My wife swore on Allah on a certain matter while she was on my chest. She said that, “By placing my head on your chest and by touching you, I swear on Allah…(on certain things)……”.
My question is, as she swore on Allah is there any shirk involved as she said “by placing my head on your chest and by touching you”? She confirmed me about her niyyah; she said about placing her head on my chest and about touching me was only to emphasize on the oath which she was taking on Allah. Which means the oath was on Allah only, and the details (by placing my head on your chest and by touching you) was only for emphasize on the oath. Is there any problem in the oath or is it ok as she swear on Allah? Please answer my question. Much obliged.