I don't believe the line about her 'getting fat'. I mean, look at that flat belly! Like I keep saying, she's got tall person metabolism. She burns through everything she eats like it's nothing, just like I do, because we're both tall people with absurd metabolisms. I guarantee you that if she notices herself gaining weight, it is just her growing more, not gaining body fat. If anything, it's her breasts, butt, or thighs filling out more. That belly is likely to stay flat as a board for many years.
Maybe, eventually, when she's at the end of her teenage years, that metabolism will slow down, but it's possible that metabolism will keep raging like a fiery furnace, just like it did for me. I'm a number of decades old and I still can eat like twice what my brother-in-law and eldest sister eat and it just vanishes into the blackhole of my gut to feed my massive 6'7" (2 meter) frame.
Not saying Anna will end up that tall, but she is likely to keep growing for several more years, at least, since, again, she's only 14, and puberty can last until late teens. I'll note I kept growing into my 20s, pretty sure. Not much into them, but still.