The 81-year-old mother of the late Whitney Houston arrived at Emory University Hospital Friday afternoon, PEOPLE confirms. She was accompanied by several other people.
An observer says they looked composed and formally dressed.
Bobbi Kristina has been on life support since Saturday, when she was found unconscious in a bathtub at her Roswell, Georgia, home.
Cissy joins her former son-in-law, Bobby Brown, and other family members who have gathered in the intensive care unit all week long to say their goodbyes to Whitney's only child.
In 2013, Cissy penned an impassioned open letter to her granddaughter, telling her, "Krissi, all I want for you is your good health and happiness."
Although Bobbi Kristina remains unresponsive and can breathe only with the aid of a ventilator, Brown has not been ready to give up hope, a relative told PEOPLE earlier in the week.
"Bobby has told us, 'If America thinks she is dead, they will stop praying,' " the family member said. "And at this point, we want people to pray for a miracle."
More on Bobbi Kristina Brown:
Bobbi Kristina's Cousin: We're Still Praying, 'Though Doctors Don't See Any Hope for Change'
Family Gathering to Say Goodbye to Bobbi Kristina Brown
Max Lomas, Who Initially Found Bobbi Kristina Brown Unresponsive, Just 'Wants His Good Friend Back'
Houston Family Had Restraining Order Against Bobbi Kristina's 'Husband' Nick Gordon
Bobbi Kristina and 'Husband' Nick Gordon Were Never Married
Bobby Brown's Bedside Song to Daughter Bobbi Kristina: 'The Greatest Love of All'
Were Drugs Involved with Bobbi Kristina Brown's Near-Drowning?
Kevin Costner on Bobbi Kristina Brown: 'I Can't Imagine' What Her Family Is Going Through
Bobbi Kristina Brown's Family Keeping Hospital Bedside Vigil
Bobbi Kristina Brown Is 'Fighting For Her Life,' Family Says
For Bobbi Kristina Brown, Minutes Without Air 'Could Be Grim'
Bobbi Kristina Brown Is Still Unresponsive, According to Source
Do Bobbi Kristina Browns's Social Media Accounts Hold Clues About Why She Was Found Unresponsive?
Bobbi Kristina Brown: Inside the Troubled Life of Whitney Houston's Daughter
Bobbi Kristina Brown Hospitalized After Being Found Unresponsive in Tub
Stars Rally Around Bobbi Kristina Brown
Bobbi Kristina's Husband Is Not the Bad Guy, Says Source
Bobby Brown 'Inconsolable' Over Bobbi Kristina's Hospitalization
Bobbi Kristina Brown Recovery Would Be a Miracle, Says Source