Sarah Brooks, 1, plays with bubbles with her father, Joe Brooks, and her brother, Jordan Brooks, while waiting in an examination room during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Kenyatta Brooks holds her daughter, Sarah Brooks, 1, as she cries while waiting for her chest port to be accessed during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Sarah Brooks, 1, plays with her father, Joe Brooks, and brother, J.B. brooks, as her mother, Kenyatta Brooks, and brother, Jordan Brooks, look on during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Kenyatta Brooks holds her daugter, Sarah Brooks, 1, as nurse Mitch Wilson draws blood from a port in Sarah's chest during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Joe Brooks holds his daughter, Sarah Brooks, 1, as she undergoes a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

J.B. Brooks plays with his sister, Sarah Brooks, 1, while waiting in an examination room during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Kenyatta Brooks and her daughter Sarah Brooks, 2, play with toy cars in the playroom while waiting for Sarah to undergo her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

J.B. Brooks, right, tries to calm his sister, Sarah Brooks, held by her father Joe Brooks, as she is examined by physician's assistant Tom Killmond during a chemotherapy treatment at the Johns Hopkins Children's Center Aug. 19, 2013.

Kenyatta Brooks is comforted by her husband, Joe Brooks, after learning that their daughter, Sarah Brooks, 1, will need to return to the hostpital the next day because of a low platelet count during a chemotherapy treatment at the Johns Hopkins Children's Center in Baltimore Aug. 19, 2013.

Jordan Brooks, 9, holds his sister, Sarah Brooks, 2, while wearing a custom T-shirt showing his support during her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Sarah Brooks, 2, rests in a hostpital bed with her brother Jordan Brooks, 9, while waiting in an examination room during her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

J.B. Brooks, 11, holds his sister, Sarah Brooks, 2, in front of a princess-themed banner celebrating her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Kenyatta Brooks, center, cheers with family members, from left, Yvette Brooks, Keshawn Cartnail, and social worker Lori Seraphin as her daughter, Sarah Brooks, 2, undergoes her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Kenyatta Brooks high-fives her daughter, Sarah Brooks, 2, as she sits with her father Joe Brooks after receiving her final chemotheraphy treatment from nurse Elizabeth McGrain at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Sarah Brooks, 2, is held by her father Joe Brooks as she looks down on the traffic below from an eleventh-floor window while waiting to undergo her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Sarah Brooks, 2, runs through a skywalk followed by family members after completing her final chemotheraphy treatment at Johns Hopkins Children's Center in Baltimore June 2, 2014.

Sarah Brooks, 3, reacts while coloring next to Deshawn Johnson, 4, at New Beginnings Christian Learning Center in Taneytown Thursday, Oct. 15, 2015.  Roughly a year and a half after her diagnosis, Sarah has returned to school.