You could use any Pelargonium, other than a trailing or miniature type. (Geranium in common parlance). If the neighbour is willing you could even get cuttings of hers. Since hers are so old that will explain the size. They are pretty straightforward plants and can be overwintered in a frost free greenhouse porch, etc. A Googlesearch will get you many. many sites to tell you how to grow Pelargoniums. Here's one:

Here is a link that might be useful: Pelargoniums

Many thanks for the link.

My mom does this, but she doesn't have the room for all of hers indoors, so many she allows to go 'dormant': she'll store them in an insulated garage heated by a wood stove in the winter, and allow them to go fairly dry. They look completely dead end of April, and then in the leaf axials new growth will start to bud out in May. It will take until the end of July for them to really be looking good and showing off their blooms. Then in the spring when she can she gets them back outside into the sun, and they start growing again.

Our growing season is really only 4 months at the very latest, so it takes her geranium plants at least 2 months to get to where they are looking good. But once they start to bloom, look out. Easily, because of how large the plants can be (circumference of 30", 2 feet in height just for the greenery) and they will be loaded with big bloom heads, more than 2 dozen at a time. Glorious.

The ones she does take indoors will continue to grow (weakly) to the point I would want to toss them, and in the spring their growth is weak and limpy and has trouble acclimatizing to the outdoors, because the plant is so big. But they do as well as the garage ones, just at a different pace (usually a bit earlier for flowers).

So if you've got the space indoors where you can start growing them (strong) a month or more before last frost, that would be prime!