'In attendance' means someone who was tending to the deceased during their final illness, but was not present when they died (hat tip to Harry Vervet at https://genealogy.stackexchange.com/a/15587/6485).
She died (recorded) at 14 Heavitree Road -- you can't infer anything from this single piece of data, other than where she died.
Her usual address (based on Rank or Professions) was 13a Trinity Street where she (probably) lived with her husband Edward Goode. And, given the address of her son (the informant), her son lived with her and her husband as well.
But she died at another address.
Very often, death certificates in this period gave a seemingly ordinary address for a hospital or workhouse. Given that she died of something that sounds like it might have been cancer, I would investigate this possibility.
According to The Workhouse the Exeter Workhouse was at 14 Heavitree Road.
So, she died in the Workhouse Infirmary -- not unusual in this period when it was the only place many people could access medical care.
The whole certificate reads:
Registration district Exeter
1923 deaths in the Sub-District of EXETER WEST in the County of EXETER
(C.B.) [County Borough]
When and where died: Sixteenth January 1923 14 Heavitree Road U.D
Name and surname: Norah Goode
Age: 62 years
Rank or Profession: of 13A Trinity Street Exeter U.D. [Urban District]
Wife of Edward Goode a Fish Salesman
Cause of Death: (1) Epithelioma Palate (11) Ashthenia Certified by J
Pereira Gray M.D
Signature Description and Residence of Informant: Frank H. O'Brien Son
in attendance 13A Trinity Street Exeter
When registered: Seventeenth January 1923
Signature of Registrar: A. R. Foote