One apple id and two apple watches causing confusion and frustration!

My single apple id account has worked for years with ability to cope with multiple devices shared by my family but now we have two apple watches it seems I have to create another apple id so that activity stats do not get mixed together. Is there another way?

I do not want to have to tell my wife her new Apple Watch is causing havoc with my activity stats and her stats belong to me! Sharing data, apps, photos on a single id has been a real positive up to now.