For weeks, Sonya Sotomayor has put on her best face, displaying a pleasant disposition that has somewhat fended off critics of her nomination to become the nation's first Hispanic Supreme Court justice.

A federal judge the past 17 years, 11 of them on the 2nd Circuit Court of Appeals, Sotomayor escaped the rough South Bonx streets of her childhood cheerfully immersed in Nancy Drew books and Perry Mason episodes on TV.

In the seven weeks since President Obama nominated her, Sotomayor has faced a barrage of questions about her past with no public avenues to respond, aside from carefully scripted White House statements about her rise from the housing project where her Puerto Rican parents relocated after World War II, and comments from friends and colleagues.

Critics of her selection, aware she will likely reinforce the liberal wing of the high court, have put a microscope to her past statements, speeches, rulings and the sometimes brusque questions that she's posed to lawyers over the years in an effort to portray her as an activist ideologue.

The search for who she really is escalates this week when she faces critics and supporters alike in the very public forum of Senate Judiciary Committee hearings that will be beamed across the nation on television.

So far, the nation has seen a friendly Sotomayor, 54, shaking hands with the denizens of Capitol Hill and smiling through the pain of a broken ankle that occurred as she boarded a flight from New York to Washington to visit senators who will decide her fate.

A generally sunny nature has characterized her spirited approach to overcoming a litany of heartaches that began even before she was 10, when she faced the death of her father and was diagnosed with juvenile diabetes.

"I like to laugh," she says, describing herself in an interview when she became a federal appeals court judge in 1998 as "fun-loving, very open and very human."

In Greenwich Village, where she lives, she celebrates her fondness for food and friends with frequent dinner gatherings and outings to watch dance, ballet, opera and baseball. Her romantic life has been sporadic. Her seven-year marriage to a high school sweetheart ended in divorce.

She credits laughter with easing her childhood in the projects in the late '50s and early '60s, when subsidized housing was less dangerous than decades later but lacked the comforts and quiet of the suburbs. She went to a Catholic high school, Princeton and Yale Law School.

She worked several years as a state prosecutor under Manhattan District Attorney Robert M. Morgenthau, a man Sotomayor says "I greatly admire" and someone slated to testify at her hearing. She also worked at a Manhattan law firm before she became a judge in 1992.

By March 1995, she experienced momentary fame, ruling from the bench against baseball owners and salvaging a new season after a devastating strike.

In court, Sotomayor has regularly confronted lawyers, often brisk but not belligerent in her questioning of them after thoroughly researching a case and studying the relevant law and related cases on her own. Unprepared lawyers are no match for her.

Lewis Yelin, a Washington lawyer who practices appellate law, recalled how Sotomayor encouraged lively discussions about the law when he served in 1999 as a student intern in a program she initiated after she became an appeals court judge.

"She encouraged us to give her the case as we saw it. And she might ultimately decide a different way but only after a significant back-and-forth with us, debating the law," he said.

Sotomayor has acknowledged that she is "extraordinarily intense," has had to seek out laughs where she could find them in recent weeks. Since her nomination, she has been alternately praised and pilloried.

Her foes labeled her a racial activist for siding with the city of New Haven, Conn., after it tossed out a promotional examination for firemen when minorities performed worse than their white counterparts. The Supreme Court in a 5-to-4 ruling overturned the decision two weeks ago.

She defended her membership in an all-female networking club, saying it did not practice "invidious discrimination," then resigned from it to erase it as a distraction from the analysis of her qualifications and record.

And her critics continue to highlight her speech at the University of California at Berkeley Law School where she said, "Our experiences as women and people of color affect our decisions."

The attacks have left her friends seething at times.

"I quietly gnash my teeth," said Ellen P. Chapnick, a dean at Columbia Law School who created a program in 1998 with Sotomayor to let students work at the federal appeals court. "It really brings out my mama tiger," Chapnick said, quickly adding, "I don't think she needs a mama tiger to defend her."

Friends like Chapnick know Sotomayor is unlikely to stray far from her New York City roots.

"Your childhood environment shapes your perceptions, your character, your sense of values," Sotomayor said in a 1998 interview. "To the extent that I lived in an environment wrought with poverty and the mixture of responses to it, I had perhaps a much more complex understanding of human nature."