Jada Marks' private cabin in the Crew Quarters contains a safe. The code to this safe is randomly generated, meaning it's different for everyone in every Prey playthrough. However, where to find this code is always the same.
You can find this code via the roof of the Looking Glass station, on the way to Alex Yu's office. Unless you have Hacking 4, you'll have to go to the ledge of the Looking Glass roof. You'll find a damaged electrical junction. Use your GLOO Cannon to temporarily disable this electricity. This will allow you to search Marletta Kyrkos's body.
You may also opt to repair the electrical junction to give you more time to search Kyrkos's body, but this will require Repair 2 at least.
Searching her body will give you a key to Jada Marks' Cabin and a transcribe. Once you listen to the transcribe, it will give you the keycode to her safe that you can access next time you're in the Crew Quarters.