The battle between Bobbi Kristina Brown's family (Houstons vs. Browns) has heated up as her grandmother Cissy Houston reportedly plans to take on her father Bobby Brown as he tries to get custody of her estate.

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Houston, who is the mother of late singer Whitney Houston, is said to be ready to battle her former son-in-law, Bobby, until the end.

The drama comes as Bobbi Kristina remains in a rehab facility. She was found unconscious in her bathtub in her Roswell, Ga. home in Jan. 31. That resulted in her being in a coma for almost three months. Now it looks like the family is trying to figure out what to do with her money and assets.

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According to OK! Magazine Wednesday, an insider claimed, "Cissy will fight to the grave."

Right now Bobby is only in charge of Bobbi Kristina's medical decisions. While it has been reported that Bobbi Kristina will get $20 million of her inheritance from her mother, it hasn't been confirmed what the exact amount is. She was supposed to get 10 percent of it when she turned 21 back in March of 2014. She hasn't received it yet.

"It was modified and with good reason," an insider yet.

They didn't give details but at the time rumors swirled that Bobbi Kristina was struggling with drug abuse.

Cissy's lawyer David Long-Daniels spoke on the ordeal on her behalf and said recently, "This is a family matter involving sensitive information. We hope to resolve this in a manner that is respectful of Bobbi Kristina's sensitive health information.The Houston family has always looked out for the best interest of Bobbi Kristina Brown. The family has done so all her life and will continue to do so. We trust that others have the same objective."