my opinion for what its worth is get an adult to do it your kids are too young to have the responsibility to do it unsupervised, better to have it supervised by someone that knows the snakes and their behaviour in my opinion.

If your out for 2 weeks I would not worry too much, wont do them any harm at all waiting that long.

If your feeding "live" then its more important to have some one of experience doing it and not someone that wont be able to deal with a situation that can potentially go bad.

Personally if you cant get someone with snake experience to feed them but can get someone to change the water and clean up if required I would go with the latter and feed them when you get out.

and best of luck with your surgery hope it goes well for you.