Brown comes from a musical family. Her father is a former member of New Edition, her grandmother is gospel legend Cissy Houston and her cousin is 1960s pop icon Dionne Warwick.
"People want to know if she has the gift," Yahoo! Music's Johnson said.
Brown posted a video in September of her singing a capella Adele's "Someone Like You" on her Twitter page.
Johnson thought the aspiring singer had shown some improvement since the last time he heard her, performing alongside her mother on "Good Morning America" in 2009.
But Us Weekly's senior editor Ian Drew wasn't sure Brown had grown enough.
"She's not her mother, but she's not the worst singer either," he told ABCNews.com. "With the right songs and auto tuning anyone can be big.
"I would encourage her to take her time," Johnson said. "People said the same thing about Michael Jackson's children. She needs to sort out things in life a little bit more before rushing into this adult world.
"I think she's already dealing with a lot," he said, "and I hate to see her end up in a similar type of situation as her mother."