Whitney Houston's mother Cissy "was beside herself" when her granddaughter disappeared on Saturday.
Whitney passed away aged 48 on February 11 and her funeral was held at the New Hope Baptist Church in Newark, New Jersey, over the weekend.
Bobbi Kristina, Whitney's 18-year-old daughter with ex-husband Bobby Brown, was emotionally distraught throughout the service.
Following the memorial Whitney's family had a repast together and Bobbi Kristina was nowhere to be found.
"Everyone was freaking out and calling Bobbi Kristina's cell," a source told the Daily Beast. "It was so much commotion and activity after the funeral that Bobbi Kristina just slipped away. Ms. Cissy [Houston, Whitney's mother] was beside herself."
Bobbi Kristina was allegedly found a few hours later "getting high" at a hotel. The insider reveals that the family is worried about Bobbi Kristina's welfare.
"Cissy and others won't admit out loud that Bobbi Kristina has a drug problem," the family friend said. "But they know it and have been trying to keep her straight even before Whitney passed.
"They tried to save Whitney, and it didn't work. Now with Bobbi Kristina, they fear the same thing is happening again and they won't be able to stop it either. Bobbi Kristina is all Ms. Cissy has left of Whitney. She's so tired, but she's ready to fight again to save her grandbaby."
Representatives for the Houston family state that Bobbi Kristina simply stepped away to clear her mind after the emotional memorial service.
"There was some confusion about Bobbi Kristina's whereabouts last night for a short time, but she's OK," a spokesperson said on Sunday. "She needed some time alone. She is going through a very hard time as you can expect."
Bobbi Kristina reportedly spent time in a rehab facility early last year, but representatives have declined to confirm the stay.
Whitney was found dead in a Los Angeles hotel bathroom. She fought a long battle with drugs but her cause of death won't be known until toxicology tests come back.
Whitney was buried in the Fairview cemetery in Westfield, New Jersey on Sunday, where her father was laid to rest.