Hello, and welcome to the ATP Rose forum!
Your rose actually looks like it's doing well for being a transplanted rose. Those black spots are a disease called "Black Spot". It's caused by water or humidity on the leaves, and it's kind of ugly, but it's not a fatal disease...usually. The rose may lose quite a few leaves, but it will grow new ones. There are chemicals out there that you can spray on the plant that will prevent it from getting Black spot and other problems. A lot of the people I know use Bayer All in One, or really anything labeled as a fungicide for roses. Hopefully someone else will come up with better names for you.
That's cool that you kept a family plant going. My family does that too. Is your rose growing in Florida now?
With a longer growing season, you could use the chemicals that have food and fungicide both. In colder places, you wouldn't want to add any fertilizer this late in the year. Like I said, hopefully someone else will help out--maybe our east coast people who have to spray for these issues.
good luck!