The only thing I would be cocerned about is thaty now the little devils tasted live yummies, he'll be more stubborn when it comes to frozen/thawed.
If it was only 6 weeks it hant eaten, I would've held off, as you know, snakes can go easy months on end without food. Our darwin went 8 months then ate again and went 6 months, it was only at this point Inny got fed up with wasted rats he started giving live.
The snake will eat frozen/thawed if your smear mouse blood n guts on it and its hungry enough, and it will eat chickens, but he reckons its easier to keep it feeding than muck with it anymore.

Dont worry about it, live food is natural, they die quick too. If your squeamish, then keep trying frozen, or fresh pre-killed, etc, when the snake is hungry enough, it will eventually eat.
The only drawback with waiting too long with young snakes, is that all their food goes into growth, if they dont eat much, they dont grow much.
As a result our darwin now 2yrs old is still only about 4 ft, but I must stress, its in great health, just not as big as it would be, had it not been a stubborn *** LOL
Heres a inportant warning, you probably dont need but for the benifit of new keepers, NEVER leave live mice or rats in with your snake unsupervised! EVER!
Some sites love to display gross images of half eaten snakes, the results of leaving them with live food unsupervised.
Its my opinion that if your offering live, If the snake hasnt nailed it in 10 mins (while your watching) its not going to, REMOVE THE FOOD ANIMAL!