It's a rare grandmother-granddaughter ceremony.
"This is about as touching as life gets," said Rabbi Allen Secher of Montana, who has flown to Chicago to lead the ceremony in the city's South Loop.
In Judaism, the ceremony -- known as bar mitzvah for boys -- usually marks a teen's spiritual coming of age. Not all traditions offer the ceremony to girls.
In recent years, more liberal branches not only welcome girls, but adult women who wish to experience the ceremony because it wasn't available to them as teens.
"For me, it's like renewing your vows in a marriage," said Bell, who lives in Cleveland. "It's a reaffirmation of my commitment to Judaism."
Hannah is the youngest of Carolyn and Steve Geldermann's four children. Five years ago, her mother and sister Molly shared a joint bat mitzvah ceremony. Then her twin brothers, Harry and David, marked their bar mitzvah milestone together.
Carolyn Geldermann said it was only natural for her daughter to want to share the moment with her grandmother.
"I can't see a more beautiful way to do this," she said. "I'm proud of my daughter and I'm proud of my mom."
Grandmother and grandchild each spent months preparing for the service. Among their responsibilities: chanting in Hebrew from a portion of the Torah -- the first five books in the Hebrew Bible.
"It's hard because the vowels aren't printed in the Torah," Hannah said.
Because Hannah's father is Catholic and her mother is Jewish, a priest also is participating in the service.
Doing good for others is routine for Hannah, who attends Deer Path Middle School in north suburban Lake Forest. She's rallied students to visit nursing homes and to participate in canned food drives.
That's part of living out her beliefs, she said.
"Making my bat mitzvah with my grandma is really, really special," said Hannah. "But we're both pretty nervous."