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.
"It's not that anybody has botched this search so far, but we have extensive experience finding individuals, alive or deceased," he said. "Somebody has to find Natalee for this family to have closure."
"It's just utilizing another resource," Holloway Twitty said. "I know this is Aruba's number one priority right now is to find Natalee. They want to resolve this as quickly as her family does."
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.
Upon arrival, the search team planned to meet with Aruban authorities and FBI officials to review past search routes and plot new areas, Huston said.
Specialists in land searches will cover rough terrain in jeeps while divers, using specialized sonar equipment and boats, will comb the coastline, he said. The group also will bring infrared cameras to search at night, Huston said.
"We have found remains of people three to four years after they disappeared," Huston said.
Aruban authorities accompanied by FBI observers have scoured the island on foot, in vehicles and using a helicopter with infrared equipment at night. Tourists and Aruban civilian volunteers also have conducted searches, but none has turned up any trace of Natalee.
Aruban government spokesman Ruben Trapenberg said authorities welcomed the Texas group's help.
"In the end, they are just going to be tourists searching and that's OK," Trapenberg said. "And they have specialized equipment, so that's even better."
Attorney General spokeswoman Mariaine Croes said the search team would be under the guidance of Aruban authorities.
"They will be like the FBI, in an advisory role, because the Aruban police force does the investigation," Croes said.
She said it was critical that Aruban authorities be present at any search that turns up possible evidence to make sure it can be used legally in any future trial. Evidence collected without such supervision wouldn't likely be accepted by a judge, she said.