She was eager for life.

How was she to get it?
Her room was a study in the foibles of an eager and ambitious mind.

It was full of clothes, beautiful things for all occasions--jewelry--which she had small opportunity to wear--shoes, stockings, lingerie, laces.

In a crude way she had made a study of perfumes and cosmetics, though she needed the latter not at all, and these were present in abundance.
She was not very orderly, and she loved lavishness of display; and her curtains, hangings, table ornaments, and pictures inclined to gorgeousness, which did not go well with the rest of the house.
Aileen always reminded Cowperwood of a high-stepping horse without a check-rein.

He met her at various times, shopping with her mother, out driving with her father, and he was always interested and amused at the affected, bored tone she assumed before him--the "Oh, dear! Oh, dear! Life is so tiresome, don't you know," when, as a matter of fact, every moment of it was of thrilling interest to her.