Arabella is the least complex of the main characters; she is also the least ambitious, though what she wants she pursues with determination and enterprise. What she is after is simple enough: a man who will satisfy her and who will provide the comforts and some of the luxuries of life. She is attractive in an overblown way, good-humored, practical, uneducated of course but shrewd, cunning, and tenacious. She is common in her tastes and interests. She is capable of understanding a good deal in the emotional life of other people, especially women, as shown on several occasions with Sue.
Arabella never quite finds what she wants either. Jude's ambitions put her off when they are first married, but after him Cartlett is obviously a poor substitute, though she doesn't complain. She wants Jude again and gets him, but she isn't satisfied, since he is past the point of being much good to her.
That she is enterprising is demonstrated everywhere in the novel; she has a self-interest that amounts to an instinct for survival, rather than the self-interest of a Sue that is the same as pride. And, of course, she does survive intact in a way the others don't. Though at the end of the novel she is standing by Jude's coffin, Vilbert awaits her somewhere in the city. Life goes on, in short.