Danielle Roberts is a 9-year-old student who attends Stoneybrook Elementary School and is a member of the Kids Can Do Anything Club at school. She is friends with Becca Ramsey and Charlotte Johanssen. She has a 6 in a half-year-old brother named Greg Roberts and a kitten named Mr. Toes.
Danielle is described as having a small, thin face, huge brown eyes, long lashes, and painfully thin dark circles under her eyes. She also smiles a lot and likes to make jewerly.
In Book 48, Danielle was revealed to have leukemia, having been in the hospital since last summer. She has to have chemotherapy, which helps, but it causes Danielle's hair to fall out requiring her to wear a wig or a scarf. She likes to wear a t-shirt that says "Bald is Beautiful." Danielle's hair later grows back in red.
After Danielle befriends Jessi Ramsey while she volunteers at the Kids Club, Danielle tells Jessi that she has two wishes: the first is to go to Disneyland and the second is to graduate from elementary school. Jessi is able to grant Danielle's wish of going to Disneyland through an organization called "Your Wish is My Command."
Not that long after Danielle returns from Disneyland, she goes back to the hospital for more tests, but isn't sure when she'll be able to come home.
In Book 80, Danielle returned to the Kids Can Do Anything Club after spending a lot of time in the hospital undergoing chemotherapy, but her leukemia comes back and she has to undergo chemotherapy again. She appears in a play that Mallory writes for the Kids club and gets a standing ovation.
In Book 82, Danielle's leukemia is in remission and she has a lot of energy, but her high-spirited behavior causes chaos while being baby-sat by members of the BSC. When Jessi babysits Danielle and Greg, Danielle falls down after crashing into a bookcase while wearing her mother's Rollerblades, but she isn't badly injured, so Jessi doesn't tell her parents.
When Mary Anne Spier babysits Danielle and Greg, Danielle invites Charlotte Johanssen and Haley Braddock over to play and Mary Anne catches the girls sledding down the basement stairs on an old crib mattress which causes them to get dirty.
When Kristy Thomas babysits Danielle and Greg, Danielle not only invites Charlotte & Haley, but she invites Becca Ramsey and Vanessa Pike to play as well. While Kristy is taking care of Greg (who is sick with a cold), she finds the girls in one of the bathrooms and discovers that they sealed up the shower and let the water run along with putting Easter egg dye in it which causes a flood, but Kristy and the girls are able to clean it up. Kristy talks to Danielle's mother, who brushes it off as "high spirits."
When Jessi babysits for Danielle and Greg again, Danielle invites Charlotte, Haley, Becca, and Vanessa over to play. Danielle says that they're going to play a game called "Going on a Car Trip" which Jessi doesn't see as a big deal until she discovers the girls & the Roberts' car missing. She goes outside and sees the car rolling backward and then crashing into a neighbor's car across the street. The girls are scared to death and Vanessa sustains a minor cut on her head which requires her to go to the emergency room.
After the car incident, the Roberts let Jessi know that Danielle will be free to enjoy high spirits just like any other kid, but she won't be allowed to abuse that privilege.