Good advice about the gov clinics. However I just purchase my father's meds from Fanda or a local pharmacy and have done for for years (his fruit money covers the cost ) and then about once a year he will have a check up at a private clinic (can use the gov subsidy of $3000 pa towards the consultation).
Depends on your mother's situation of course but I am astounded by the number of my acquaintances who take frail and elderly relatives to gov clinics just to save several hundred dollars per month.
Some of the neighbourhood pharmacies are way cheaper than Fanda