Tofino is great, but I went in November and it was pretty quiet – might be packed in summer. Generally anywhere around the forests and coast is pretty special – we saw bears, salmon, eagles, whales etc just while we were wandering about. If you’re going to take the trip down to Victoria then Goldstream park and Sooke potholes and the nearby coast are two lovely areas with flat walks and good paths for old hips. I sat watching the sunset at Sooke and saw seals, sea lions, porpoises and loads of seabirds and otters splashing around in the river at the potholes.
There’s usually good car parking and access at most sites of interest so you hopefully won’t have any problems with your mother.
Would also echo what others have said about the driving distances. If you have the pennies, there are some seaplane routes that can skip long drives and offer some great views. Still, you’re reasonably central where you’re based.