Van der Sloot and his friends Deepak Kalpoe, 21, and Satish Kalpoe, 18, are believed to be among the last people to see Natalee Holloway the night she disappeared.
Holloway Twitty was distributing prayer cards for her daughter around the island Tuesday when she found herself in Noord, a town in northwestern Aruba where van der Sloots' parents, justice official Paul van der Sloot and his wife, Anita van der Sloot, live.
In an interview with the Associated Press, Holloway Twitty described the interaction with Paul and Anita van der Sloot as "positive," but declined to give more details.
"As far as disclosing any of the specifics of the conversation, I don't want to do that at this time," Holloway Twitty said on CBS News' The Early Show. "But I think when I walked away from that conversation with was confirmation that we still have individuals that we need to pursue, and I know the authorities and the FBI are aware of that. I have no doubt."
Close to the house, Holloway Twitty said something inside pushed her to go the door.
"I want to make it perfectly clear, I did not have a mission that day to go to his home and enter it and have a conversation with he and his wife," she told Early Show co-anchor Hannah Storm.
"As I'm doing every day, I just want to put my face and Natalee's heart in the community with the prayer cards and the posters," she said.
Holloway Twitty met with Paul and Joran van der Sloot on the night of May 30, about 12 hours after Natalee missed her plane back home. She has described that meeting as tense and uncomfortable.
Meanwhile, a volunteer Texas rescue group has postponed until Friday a trip to Aruba to help in the search because of delays in getting permits for their search dogs, a group member said Wednesday.
Texas EquuSearch has a verbal agreement from Aruban Prime Minister Nelson Oduber to bring three dogs in, but on Wednesday was still waiting for the official papers, said Joe Huston, a volunteer diver for the group.
Holloway, an 18-year-old from Mountain Brook, Alabama, disappeared in the early hours of May 30, the last day of a five-day vacation with 124 students celebrating their high school graduation. Her passport and packed bags were found in her room.
Four men have been arrested on suspicion but no one has been charged.
Holloway's uncle, Paul Reynolds, who lives in Houston, asked for the Texas search group's help because the family was frustrated that three weeks of searches on the island had turned up nothing. On Tuesday, the group said it would bring in special dogs and sonar equipment to help search for Holloway.
When EquuSearch arrives, is expected to come with 17 volunteers, including three search-and-rescue divers, said volunteer diver Joe Huston in a telephone interview from Houston, Texas. The volunteers will stay five to seven days depending on how much they can raise in donations for trip expenses, Huston said.