Solo appeared in court Monday and was released without bail. She was ordered not to have contact with the alleged victims and to not drink alcohol.
Authorities say Solo was intoxicated early Saturday when she was accused of assaulting her sister and 17-year-old nephew. But her lawyer, Todd Maybrown, said she was a victim in the altercation.
Solo was booked into jail for investigation of two counts of fourth-degree domestic violence assault. Kirkland police said in a report on the incident that a caller reported a female at the residence was hitting people and they could not get her to stop or leave the house.
Solo did not speak in court except to answer the judge's questions.
Maybrown entered the plea and argued against the city of Kirkland's request for bail, noting that Solo does not have a criminal history and her status as a public figure makes it unlikely that she would not appear when called back to court.
"There's going to be a very strong defence in this case," Maybrown added. He did not object to the city prosecutor's request for a noncontact order.
Solo's next court appearance is scheduled for Aug. 11.
Solo's 17-year-old nephew told police she was upset and appeared to have been drinking when she arrived at a family gathering. She and her nephew got into a fistfight after arguing about his acting aspirations and she called him fat and crazy, according to court documents. When the boy's mother tried to break up the confrontation, Solo punched her in the face, the documents said.
The nephew broke a broom over Solo's head and the teen pointed a broken BB gun at her and tried to get her to leave, the documents said.
The boy told police, "We just let her back into our lives," and said Solo "always does this."
"Hope is not guilty of any crime," Maybrown said in an email to The Associated Press on Saturday. "In fact, our investigation reveals that Hope was assaulted and injured during this unfortunate incident. We look forward to the opportunity to present the true facts in court and to having this matter behind Hope very soon."
Solo's husband, former Seattle Seahawks tight end Jerramy Stevens, was also in the courtroom Monday but declined to speak to the media.
Stevens and Solo were married in 2012. He was arrested just before their wedding for investigation of assault after a disturbance involving Solo, but he was not charged. Maybrown represented Stevens in that case.
Solo said soon afterward that there never was an assault and that she and her new husband were happy.
The 32-year-old Solo has won two Olympic gold medals with the U.S. women's national team and also plays with the Seattle Reign of the National Women's Soccer League.
Statements from both the team and U.S. soccer said they were aware of the situation but did not have any further comment.
Solo most recently appeared in goal for the U.S. women's team in an exhibition against France on June 14 in Tampa, Florida.
Solo had her fourth shutout of the year and the 71st of her career in the 1-0 U.S. victory, matching the national team record set by Briana Scurry.
She did not appear in the team's second match against France on Thursday night in East Hartford, Connecticut, because of a "family commitment" the team said. Ashlyn Harris started in Solo's place for the 2-all draw.
The U.S. women's team does not have any additional matches planned at this time before October's CONCACAF qualifying tournament for the 2015 World Cup in Canada.
Despite the team's success on the international stage in recent years, the U.S. women haven't won a World Cup title since 1999
AP Sports Writer Anne Peterson contributed to this story from Portland, Oregon.