i dont really know what answer to give you for how much they grow in a month since they each seem to grow at different rates. but as far as feeding, i would try getting some rat pups if you can and feed those. much easier to switch over to rats when they are younger and the sooner the better. my little girl is just a bit larger then your snake and she eats them with no problem and just the slightest lump for about a day. you can then move em up to a larger size rat pup. i know not everyone has easy access to rat pups so an adult mouse would be about the equivalent. best bet if you can have frozen feeder is to get a bag from somewhere like rodentpro.com and there will be enough variety in a bag of 25 for you to start em on somethin small and gradually move up. this is what i have been doing with my little girl and it has been working great.