i went through this a couple of years ago. My surgery was planned so I agreed with my neurologist to slightly increase my dose of stalevo for a few weeks beforehand and a few weeks after the surgery. One issue that did arise was getting my parkinsons drugs on time. I ended up taking control of the parkinsons drugs myself and left the hospital staff to look after the pain control drugs.
i must say the entire experience was miserable and I ended up on large doses of antibiotics which left me feeling wretched for several months.
I hope your mum makes a full recovery