No, this isn’t the plot for some Benjamin Button sequel, ABC News is reporting Brooke Greenberg, a 16 year old girl who is the size and mental capacity of a toddler. I don’t even know where to begin listing the possibilities rattling around in my head.

Brooke weighs 16 pounds and is 30 inches tall. She doesn’t speak, but she laughs when she is happy, and she clearly recognizes the people around her. She has three sisters: Emily, 22; Caitlin, 19; and Carly, 13. All three are bright, active and of normal size and development. They say that Brooke has ways of expressing herself like the teenager she is.

“She looks like a 6-month-old, but she kind of has a personality of a 16-year-old,” Caitlin said. “Sometimes we joke about how she rebels.”

In her first six years, Brooke went through a series of medical emergencies from which she recovered, often without explanation. She survived surgery for seven perforated stomach ulcers. She suffered a brain seizure followed by what was diagnosed as a stroke that weeks later left no apparent damage.

At 4, she fell into a lethargy that caused her to sleep for 14 days. Then, doctors diagnosed a brain tumor, and the Greenbergs bought a casket for her.

“We were preparing for our child to die,” Howard Greenberg said. “We were saying goodbye. And, then, we got a call that there was some change; that Brooke had opened her eyes and she was fine. There was no tumor. She overcomes every obstacle that is thrown her way.”

Brooke’s doctor said the source of her sudden illnesses remains a mystery.

“We love her just the way she is,” Melanie Greenberg said. “We don’t want to change her.”

Added Howard Greenberg, “Brooke is the nucleus of our family. What if Brooke holds the secret to aging? We’d like to find out. We’d like to help people. Everybody’s here for a reason. Maybe this is why Brooke is here.”