Misreading!
Small prey equals small growth. My 1,100G boa eats a medium rat (110-130G or so) every 3 weeks and gains 30-50G a feeding.
No way she went from 7G to 30G and then back to 9G.
If she went from 7G to 9G in 35 days, that sounds good.
My female Corn snake (baby), went from 22G to 28G in the past 30 days eating a meal every 5-6 days that averaged 4-5G each. I imagine you are feeding much smaller prey than that.
Either way she looks great and congrats on a wonderful little hoggie! I wanted one, but can't take the risk of a bite because I am immune suppressed due to a kidney transplant. I ended up with an Albino Carpet Python instead. Not too bad. However, I am still living vicariously through you and other Hognose owners. SOOOOO CUTE.