Well that in itself has a wide variety. There are even plenty of plants that muggles have access to that have medicinal purposes. After all, it's what their medicine often comes from I've been told.

I assume your mother would have all the basics already, correct? At least, the ones that can be easily gotten in England. I could arrange for some of my own to either be transported from Italy, or even go through what I already have here to add something new.

Off the top of my head there's lavender which helps with stress and depression, basil which is good for lowering fevers and dealing with insect stings, calendula is good for an antiseptic, and helps detoxify. Fennel's always good for digestion problems and juniper is good for anyone with problems with their joints. Though you don have to be careful with that one, it can cause problems for pregnant women.

Would you like me to continue?