Tasdia's sister-in-law, 18-year-old Dil Ayash, received serious injuries and she is in critical condition.
She is receiving treatment at Cox's Bazar District Sadar Hospital, said ADIG Md Amir Zafar, captain of Armed Police Battalion (APBn)-8.
He said the gunfire erupted at Maynarghona Rohingya Camp No. 18 on Tuesday.
A gang of armed assailants targeted various homes in Block H-52 and opened fire indiscriminately on residents of the camp on Monday night, leaving the Tasdia and Aysha injured.
They were rushed to Ukhiya Upazila Health Complex, where doctors declared Tasdia dead.
Being informed, APBn personnel went to the camp. They, too, were shot at by the assailants, but the gunmen fled when law enforcers returned fire.
The APBn is currently on the hunt for the assailants, according to Zafar.