DESPITE perceptions to the contrary, most American parents and children report a rewarding family life, though they acknowledge the challenges are daunting, according to surveys released yesterday by the National Commission on Children.Constraints on time and money and concerns about safety are real for most families, especially in the single-parent households that now account for one in four families, the reports found. Even so, parents are working extra hard to help their children thrive, they say. Sen. Jay Rockefeller (D) of West Virginia, chairman of the commission, predicts that "the family" will become one of the buzzwords of the 1992 presidential campaign. "I'm certain that there will be an instinct to use the American family in this election as there was an instinct to use the American flag in the last election," Senator Rockefeller said in a briefing. Congressional Democrats are competing with various proposals to provide tax relief for the average working family - an issue that just got a tremendous boost by Democrat Harris Wofford's upset victory over Bush administration insider Dick Thornburgh for the Pennsylvania Senate seat. "The message in Pennsylvania [was], 'We don't like the corridors of power; we want change, says Rockefeller. "In that case it happened to be more in health care. But that was a symbol for, 'We want attention; we're out here fighting for our lives and it's very tough to make it and nobody seems to notice. In one survey, when speaking about the condition of the nation's families, American adults painted a sad picture. Some 86 percent said today's parents often aren't sure of the right thing to do in raising their children. And parents often don't know where their children are, 76 percent of those surveyed said. In addition, 87 percent said parents have a hard time making ends meet, and 81 percent said parents don't spend enough time with their children. More than 50 percent reported that children are worse off today than they were 10 years ago in moral and religious training, discipline, and time spent with parents. But, in a separate survey, when parents and children were queried about their own relationships, the results were markedly different. Among families from a range of incomes, ethnic backgrounds, and circumstances (both single- and dual-parent), all but 3 percent of parents reported that relations with their children were "excellent" (65 percent) or "good" (32 percent). Parents reported spending a lot of time with their children every week. For example, 70 percent reported their families eat dinner together five or more nights a week. Almost all parents said they know all or most of their children's friends. And 88 percent said they know "all or most of the time" what their children are doing when they're not home. Children reported good relationships with their parents: 94 percent named their mothers as special adults in their lives; 82 percent named their fathers. The apparent discrepancy in the two surveys comes from adults "looking around them and [being] very concerned about what's happening to families, about the images they get through the media," says Kristin Moore of Child Trends Inc., who designed the surveys. "But, living their own lives, they know they care about their children and they're doing the best they can." "You tap a little further," Ms. Moore adds, "and you find ... some groups are having an overwhelmingly hard time." The second survey found that 60 percent of parents want more time with their children, but that many must work long hours to make ends meet. Of the parents surveyed, 55 percent said they worried at least some of the time that their income would not meet expenses. One of the most striking survey results concerned fears for children's safety. Almost half of the parents said there was no safe place in their neighborhood for their children to gather except in their homes. Hispanic parents were five to 10 times as likely as white parents and twice as likely as black parents to worry "a lot" that their children will be shot, get involved with drugs, become a teen-age parent, or get AIDS.