(Photo: INFDaily)

Bobbi Kristina has spoken to Oprah Winfrey in her first interview since the death of her mother, Whitney Houston. It’s unknown at the moment how many unanswered questions the 18-year-old will address, including about her own drug use.

Houston, 48, died suddenly on Feb. 11, on the eve of the Grammy Awards, and all indications point to a combination of prescription drugs and alcohol as the cause. But the coroner is still awaiting toxicology tests.

Bobbi Kristina was at the Beverly Hilton hotel when her mother died and was reportedly hospitalized twice and put on a suicide watch following the discovery of her mother’s body in her hotel room bathtub.

It’s unknown whether Bobbi or her relatives will address how Whitney’s casket photo was taken and published in the National Enquirer. There have been reports that the Houston family knows who took the photo, but no details have been released so far.

Among many other unanswered questions is whether Bobbi Kristina herself is using, or has abused, drugs. Also unknown is the state of her late mother’s finances, how Bobbi plans to provide for herself and where she plans to live.

In addition to Bobbi, Winfrey spoke with Whitney’s sister-in-law and manager Patricia Houston and Houston’s brother, Gary Houston. According to Winfrey’s network, they will discuss how they hope Whitney is remembered and will address some of the rumors.

Whitney’s sister-in-law Leolah Brown told Access Hollywood that she is concerned about her niece. “Krissy is not safe right now. I want to say to Krissy that it’s very, very, very important that she does not trust anybody at this time.”

There have been reports that Whitney’s estate could generate several million dollars a year. At least three of her songs are riding near the top of the charts in sales. Other reports claim, the singer owed so much to her label it may be years before survivors see any income.

It’s unknown how probing the interview will be. The former daytime talk show queen has been a friend of the family for years and Oprah even attended Houston’s funeral in Newark.

The interview will run on “Oprah’s Next Chapter” on OWN: Oprah Winfrey Network, Mar. 11, 9 p.m. ET/PT. The network will also re-air Oprah’s 2009 interview with Whitney before the interview.