Captain Hellmann commissioned as a Second Lieutenant in May of 2021 after graduating from Miami University. Lieutenant Hellmann checked in to The Basic School in October of 2021 where she was assigned the MOS of 0802. Upon completion of The Basic School, Lieutenant Hellmann attended Marine Artillery Officer Basic Course (MAOBC) at Fort Sill, Oklahoma from May 2022 to October 2022.
After graduating MAOBC, Lieutenant Hellmann reported to 3d Battalion, 11th Marines, where she was assigned to India Battery as Headquarters Platoon Commander and Fire Direction Officer. From October 2022 to August 2023, she executed three Battery level exercises to include TACP 1-23, and four large scale training exercises in support of 7th Marine Regiment Reinforced, to include Steel Knight 23 and Service Level Training Exercise (SLTE) 2-23. In October of 2023, Lieutenant Hellmann deployed with India Battery on UDP 24.1 to Okinawa, Japan. While in Japan, she supported Artillery Relocation Training Program (ARTP) 23.4, a bilateral training exercise with the Japanese Ground Self Defense Force in Hokkaido, Japan.
In May of 2024 First Lieutenant Hellmann returned from UDP 24.1, executed TAD orders to 3d Battalion, 4th Marines, and was assigned as Lima Company's Fire Support Officer and Headquarters Platoon Commander. Lieutenant Hellmann executed SLTE 5-24 and then deployed with V34 to UDP 25.1 in October of 2024. During her second UDP, Lieutenant Hellmann spent two months at Camp Fuji in support of joint exercise Shinka 24.2, and Fuji Viper 25.1. For the remainder of UDP 25.1, Lima Company fulfilled the Alert Contingency MAGTF (ACM) mission and supported the 31st MEU's Certification Exercise (CERTEX).
First Lieutenant Hellmann returned to MCAGCC Twentynine Palms in May 2025 and received orders to Second Battalion, Fourteenth Marine Regiment.
In May 2025, Captain Hellmann checked-in to Battery F to assume duties as the Battery Inspector-Instructor.