Lea, in Darwin we lived in a town house with a very similar layout to teh palce you describe! We had a stairgate at the top (as we lived upstairs, bedrooms downstairs)

More recently in Adelaide in our old house we lived on a steep block that had front steps (lots) to get to the front door, adn steep back steps from the deckk to the garden.......

And now in our new house we have a curved stair case that leads from the entrance hall to some of the bedrooms/retreat.

We have stair fates, although just helping them up and down really seemed to help them get used to getting up and down safely.

We taught her to go down backwards at first (so a backwards crawl) and then when she and we were more confident we held her hand and taught her to use the railings. This included swapping sides when she went around the corner.
This is the same method that we have adopted!