It may just be company policy, then. Every petstore I've been to has said they can't sell them as feeders. We have one local place, but one of my garters picked up a nasty parasite from some of their pinkie mice; idk how long they were freezing, but they looked a bit sketchy. I can try there though. Better than her starving...
My husbandry (according to this forum when I asked) is correct. Humidity 50-60%, Ambient temp 83-84, Hot spot 90, hot and cool hides, and plenty of hiding spots. She was in about a 15 gallon tub, but she is currently in something that is a bit over 5 gallons, as someone recommended a smaller area (the small one was actually what she was in when she ate her first two meals).
I'll get some pics up tomorrow. A gram-scale is on my list of things to get once my husband can find a job, but I don't have one atm (not really a necessity with garters unless you're breeding).
I've never dealt with constrictors before, so I'm having a hard time determining where the point of 'worry about health' would be. Her metabolism is so much slower than any of my other guys it's been a little unnerving!