She probably had the aneurysm for a long time that steadily became larger and one day burst open causing bleeding inside her brain.
The recovery after treating a ruptured aneurysm
depends on the amount of bleeding that has already taken place and the patient's condition at the time of admission.
For example a patient with just headache will recover quicker that a patient in coma
If she was unconscious when she was admitted and had a big bleed, then the recovery can be long and can leave residual neurodeficit if the patient survives.
I hope this helps you understand.
Neuro-Vascular Inteventional Radiologist