WASHINGTON (AP) _ Lisa and Guy McMullan said Tuesday that they suffered through his unemployment, first on a farm in Miles City, Mont., and then in construction and at a steel plant outside of Baltimore, and were forced to move into a homeless shelter with their four young children.

However, they told a House committee, they refused to break up their family, even though that might have made life easier for them.

''It's hard to stay together out there,'' Mrs. McMullan told the House Select Committee on Children, Youth and Families. ''We're trying to get back to a normal family household where the mom and dad control the lives of their children, and not a shelter director or some other outsider.''

Mrs. McMullan said she called several shelters in Baltimore late last year, ''but no one would take us as a whole family. Finally, the Salvation Army offered us a room to stay in.''

McMullan said other organizations ''were willing to take the mother and children but not the father. We weren't going to break up our family. There were times when we were really down, but fortunately we had each other to lift the other up.''

The McMullans, of Dundalk, Md., and their children Jamie, 10, Ryan, 7, Morgan, 3, and Ryder, 2, were part of two panels which offered the committee testimony on the homeless, especially its effect on children and families.

Chairman George Miller, D-Calif., said, ''We have always taken for granted in this country that every American, no matter how affluent or impoverished, has a roof over their head. In the America of 1987, however, that is simply not the case.''

Miller said, ''Whether resulting from the scarcity of affordable housing, or the inadequacy of public benefits, or a lack of jobs, or an increase in family crises - or some combination of these - the reality is that a significant portion of the nation's homeless population are families with children.''

Another witness, Yvette Diaz, 12, lives in New York's Martinque Hotel, where the city places many homeless families, but doesn't like it very much ''because there is always a lot of trouble there. Many things happen that make me afraid.''

She said she doesn't have any place to play. ''The streets are dangerous because there are all kinds of people who are on drugs or are crazy,'' she said. ''My mother is afraid to let me go downstairs.''

Yvette, who lives with her mother, two sisters and brother in a two-room apartment, said only last Saturday, a security guard at the hotel was shot and killed on her floor.

''If I could have anything that I could want I wish that we could have our own apartment in a nice clean building and a place that I could go outside to play in that is safe,'' she told the committee. ''I want that most of all for me and my family.''