Looking at the symptoms, they fit with cerebellar issue, as the cerebellum is responsible for modulating movement and aiding in coordination and balance. [FA2020 p499]
She does not have paralysis or parasthesia but rather lack of control of movement, making injury to the cerebrum less likely. Further, her issues are not localized to the upper or lower extremity and do not fit with any syndrome of spinal cord. Ataxia is also typically a buzzword for associations with the cerebellum. In this case, her limb ataxia is likely from a metastasis to the left cerebellar hemisphere.
If you want to review:
Common brain lesions can be found FA2020 p511.
Spinal lesions can be found FA2020 p530.