For that size the feed intervals seem right, that's how often I've done it in the past. 131 grams seems a bit small for a 3 month old BP but nothing alarming. A few ideas would be to perhaps switch to mice of the similar size instead of rats or if possible switch to live mice for a while. My Fire and Super Pastel were picky eaters at first so I switched to live mice and after a few months switched them to f/t rats and they are great eaters now. On that note I also have a normal that is still refusing f/t anything, so every week I have to make a special trip to Petco just to get one mouse for him.