HOUSTON --Several children's graves may be mismarked and their families may not even know about it. The problem is at the Forest Park Lawndale Cemetery in southeast Houston. This all came to light because of one Houston-area family. They started asking probing questions about their own loved one's gravesite. They'd been visiting it for nearly two decades. "The cemetery was put these here so I could mark my son's grave," LeAnn Farrell said. For 16 years, LeAnn Farrell and her family have been coming to same spot at the Forest Park Lawndale Cemetery. "We stuff every time, every time. We bury cards, toys, key chains," Alicia Farrell said. The baby Farrell, lost during her pregnancy all those years ago after a bad car wreck, is buried there -- or so they all thought. "They don't know for sure. They're just assuming," LeAnn Farrell said. This week, the family was finally going to put a headstone on Stanley Irwin's grave. "If you look on this paper here, and you go by the numbers on the papers, it don't match," Robert Irwin said. Their plans suddenly changed when they say a cemetery employee told them they've been visiting the wrong grave all this time. Farrell was furious. "Where I was sitting was someone else's little girl," LeAnne Farrell said. When we first asked general manager John Krasnick questions, he wasn't eager to answer them. "How is it that the plot information doesn't match how the graves are marked? I think that's a fairly simple, straight forward question. "I don't know that it doesn't," he responded. Krashnick agreed to meet with the family and about three hours later, they received some unexpected news. Farrell says she was told her son's grave is marked correctly but that several other children's graves may not be. "We don't know if the markers were placed incorrectly or if they shifted. While the folks at Forest Park found there was a problem, they are going to work with four families to correct the problem," funeral home spokesperson said. Farrell says her heart goes out to those families who may not even know about it. "I think all the mothers and fathers, sisters, brothers -- it doesn't matter -- need to know where their children are," LeAnn Farrell said. The funeral home spokesperson stopped short of calling this a mistake and instead called it problem because it's unclear what exactly happened. We'll keep you posted on what we find out.