What Helena was like at this age:            

"When Biddy saw him her cheek exhibited the prettiest pleased, surprised red that he had ever observed there, though he was not unacquainted with its fluctuations, and she stood still, smiling at him with the outer dazzle in her eyes, making no motion for him to enter. She only said: "Oh, Peter!" And then: "I'm all alone."
"So much the better, dear Biddy. Is that any reason I shouldn't come in?"
"Dear, no - do come in. You've just missed Nick; he has gone to the country- half an hour ago." She had on a large apron, and in her hand she carried a small stick, besmeared, as his quick eye saw, with modeling clay. She dropped the door and fled back before him into the studio, where, when he followed her, she was in the act of flinging a cloth over a rough head, in clay, which, in the middle of the room, was supported on a high wooden stand. The effort to hide what she had been doing before he had caught a glimpse of it made her redder still and led her to smiling more, to her laughing with a charming confusion of shyness and gladness. She rubbed her hands on her apron, she pulled it off, she looked delightfully awkward, not meeting Peter's eye, and she said: "I'm just scrapping here a little- you mustn't mind me. What I do is awful, you know. Peter, please don't look. I've been coming here lately to make my little mess, because mamma doesn't particularly like it at home. I've had a lesson from a lady who exhibits; but you wouldn't suppose it, to see what I do. Nick's so kind; he lets me come here; he uses the studio so little; I do what I please. What a pity he's gone- he would have been so glad. I'm really alone- I hope you don't mind. Peter, please don't look."
Peter was not bent upon looking; his eyes had occupation enough in Biddy's own agreeable aspect, which was full of an unusual element of domestication and responsibility. Though she had taken possession, by exception, of her brother's quarters, she struck her visitor as home at home and more herself than he had ever seen her. It was the first time she had been to his vision so separate from her mother and sister."

from "The Tragic Muse" by Henry James

The Dormer family in the "The Tragic Muse" is loosely based on the deKay family. Nick is Charles deKay, Lady Agnes is Helena's mother and Grace, her older sister, all changed of course for literary reasons (and set in England and France- and the mother is anti-art, which is real silly). Helena's made a sculptress instead of a painter. But Henry has captured her- this is why men fell in love with her a first sight- women too. The chapter goes on (XXIX) and rounds her character out even further.