accessing size of f/t feeders

[Dark Lady Kat]

I have 2 that hatched on 08/23/2012and they are just at 120ish grams, there were problem feeders to start with, their sister is almost 400g
There are too many variables to try and say what a snake should weigh in my opinion.

well at 84 g I would think it is safe to say they are probably only half the size they should be? and with that weight would you keep them on hoppers for now offering one every 3-4 days until they double their weight then start uping the size and time between feedings? and continue feeding them that way until say mid to end of january giving them aprox 2 months to pack on some g's?