Awesome pictures man, well done, I really like your set up, it looks great. I like the colors and use the same tortoise shell for my Carpet Python who's about 6.6 Feet and I'm going to start covering it the way you have it.
In regards to Eco Earth, I've never had a snake that would get it in their mouth due to tongue flicking so I can't comment on that but my snakes definitely get some in their mouths if they attack a prey pretty hard and roll around. From my knowledge on reptiles though, not just snakes, a little Eco Earth can't harm them if digested, they get a lot more Nature in their mouths in the wild and their stomachs are incredible. The only concern I've read from others on here is if a bigger piece gets stuck somewhere at the beginning of their mouths, but I go through all my substrate to make sure no bigger pieces are present.
Owning 1 snake is great cause you can just focus all your attention and money lol on just the one.
Keep us updated though, would love to see her as she grows and if you build a bigger tank.
Good luck to you and her