Apple Watch

I was wondering if anyone knows if you can use a watch with an iPhone that does not have cellular? This would be for a child with diabetes who has a pod they have to wear and an app on the phone that alerts them of their blood sugar. Instead of having the child have to check their phone for alerts, ideally the watch would just go off. The child has to carry the phone because it has the app on it but it is preferred to only have the iPhone able to work through Wi-Fi and not have cellular activated.