How often does Nessie grow

Well, the book says she will be full grown after seven years. I did the math, and basically she grows about two and a half times faster than a regular human does.

she grows every day

every day

Nessie is growing constantly, but at a più accelerated rate than normal humans; however, as time goes one, the rate of her growth decreases. She'll reach full physical maturity at around the age of seven.

Every day