AS the two-year anniver­sary of Whitney Houston’s death nears, sources say her troubled daugh­ter Bobbi Kristina has sparked a family war by marrying her “brother” Nick Gordon!

The drug-plagued newlywed will inherit $2 million when she turns 21 on March 4, and family members fear that Nick, who’d been unofficially ad­opted by Whitney, rushed her to the al­tar for the money.

Even worse, in­siders say Bobbi Kristina – called Krissi by the family – has no pre­nup to protect her fortune.

“The entire family is devas­tated over this marriage,” said a source close to the Houston family.

“Ever since Whitney died, Krissi’s grandmother Cissy Houston, her Aunt Pat and Uncle Gary have been trying to get rid of Nick. They felt he was just hanging around to get his hands on Krissi’s money.

“But Nick worked on Krissi 24/7, saying that he loved her and would protect her.

“Now he’s married her – just in time for her 21st birthday.”

Whitney was just 48 when she was found dead in her bathroom at the Beverly Hilton Hotel on Feb. 11, 2012.

In her will, she stipulated that Krissi receive 10 percent of her $20 million estate on her 21st birth­day, another 6 percent on her 25th birthday and the remainder on her 30th birthday.

While Whitney took in Nick as a 12-year-old and acted as his guardian, the tragic diva never for­mally adopted him, and sources say that’s led to this disaster.

“Krissi’s relationship with Nick was never romantic until after Whit­ney died,” said the source.

“The family feels that if Whitney had adopted Nick and left him an inheritance, he never would have pursued Krissi.”

As The ENQUIRER has reported, Krissi has battled booze and drug demons for years. In February 2011, we published photos of her using cocaine as a teenager.

While Krissi later entered rehab, sources say she turned to alcohol and drugs to cope with her mother’s untimely passing.

“Boozing and using drugs was just normal for her and Nick,” revealed the source.

 “Now the family fears it will be just a matter of time before they blow her inheritance on drugs and partying.

“And they know Krissi didn’t protect herself with a prenuptial agreement. But legally she’s old enough to make her own decisions, so there’s nothing they can do.”

While the couple has reportedly told pals that Krissi’s grandmother had given them her blessing, that’s simply not true, according to the source.

“When Cissy found out that Krissi had married Nick, she was in tears,” said the source. “She’s hurt and fu­rious. There’s no way she gave Krissi her approval.

“But Cissy says that she’ll be there for Krissi when she’s ready to talk. Cissy just hopes it won’t be when Krissi calls to say she’s broke and doesn’t know where to turn.”