Complex sentence: Arriving at the 55 as a firefighter, it was revealed she used to be a paramedic before "moving up" to the fire squad, and often worked as a medic during her time at the 55.
Split into simpler sentences: Arriving at the 55 as a firefighter, it was revealed she used to be a paramedic before "moving up" to the fire squad. She would often work as a medic during her time at the 55.