Can the Apple Watch be used without an iPhone?

I would like to buy my daughter a watch to phone from and receive messages but mainly for tracking. I know I need to buy a cellular connection with this. I do not want to buy her a phone too. Would this work? We have other Apple devices in the house that we could use to set it up with but I wouldn't want message/calls for me to go through to her watch. Can anyone advise?

[Re-Titled by Moderator]