Honestly, 30 inches may seem small, but snakes can differ with metabolism. My red bull that is an 04 as well is probably between 30-36 inches, so she may be similar to yours.
You can have one snake that grows with just thinking about eating a mouse, and then you can have snakes that for reasons unknown, do not grow as fast.
That is ok though. Your 04 triple het female may simply have a faster metabolism. I don't think being thick though is good, you may want to keep an eye out for that, as if she is really thick, that may lead to health problems. Obesity in reptiles is hard to get around.
I think everyone's advice on your red bull regurging is great. I would not be feeding that snake more than one mouse at a time, as I feel that is what led to it regurging. Also remember, if one snake does fine with eating two, that does not mean all snakes will. As far as thickness, keep in mind what is the healthiest for the snake as well. In my personal opinion, I would rather have a leaner than thicker snake. When I see some of my snakes getting thicker, from of course, lack of exercise, I skip their meal for the week.
Take care and keep us posted!
Billy
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Genesis 1:1