If Anna continues to have her mom's body type, she's got nothing to worry about, haha...
https://www.instagram.com/p/Bz_IzACISoW.
I agree on the shortcomings of her technique, though. I don't think it's owing to a lack of strength. If you ever see her up close, she's a lot more athletically built than initially meets the eye. Maybe not as much so as Sasha, but not too far off. It probably has more to do with the fact that she's been with Eteri the longest, and never learned proper technique early on as Alena did.
It's for that reason that of the three of them, I'd most like to see Anya leave Eteri. Nothing against Eteri, but I think great skaters benefit from having multiple instructors over the course of their careers, and Anna's never really had that.