I agree with Jamie. While the snake looks thin, it doesn't look emaciated and on the verge of death.

I would definitely get that fecal done though, then I would sterilize the bejeezus out of that enclosure and all the stuff inside.

My second snake was at least a year old, but only weighed 165g. They only fed the poor thing mice pinkies. If you feed appropriate sized prey items, you should see good growth (unless there is a problem with parasites or protozoa)