Marie Delacroix has contacted me and told me to come find her in Cargo Bay A. However I've searched through both the shuttle bay cargo area (one is blocked off) and the main cargo hold without finding her. Where exactly is she?
It's an unfortunate lack of clarity in the dialogue.
She's in a different Bay A, which you'll get to much later. It, (and she) is impossible to miss at that time.
Specifically, there is a second, separate set of Cargo Bays on Deck 6, at the shuttle hangar. After you blast open the doors to the shuttle bays, you can find Delacroix's body in the wreckage. Note that if you inspect her body and take the audiolog there, SHODAN will not be pleased. She will take 20 Cyber Modules from you and become audibly enraged. It's worth it for the scene though, IMO.