Yes, they do.

The gondolien is indeed for two Persons but it is comfortable. We visited the place outside the peak tourist season and did not need to queuing for the ticket office. July might be different. Better to reserve time for that or check out if the have online booking which could make it quicker. If you have time it is also nice to walk back instead taking the gondola. On the walking trip back to the village you see lovely wine fields and a monastery with their winery.

before I was born 1954

The cable car is open during the Christmas Markets

Are you on the river cruise from Holland To Switzerland - Viking River cruises uses one of the main docks available on contract. After crossing the road and railway you look for hotel post and hotel droselberger. The drosselgasse is between these. A very narrow vine covered alley way with lots of wine cellars. A Rüdesheimer is essential!!! Once at the top turn right and you follow the cobbled path, you cannot miss the cable car. When you are up there you can walk the woodlands away from the cable car you used and go down a different one to assmannshousen and then jump a ten min train ride back for around €2.50 per person - Towards Hamburg not Köln. It is the same side as the station house. Feel free to ask further questions and Bon Voyage!

It is a cable car, but open to the elements, I'm not sure if they allow an adult and child to sit together on one side, it's like swing boats.

Sorry John, the cable car was closed when we went so we cheated, caught a taxi up and took the walk back down through the vineyards. The best walk ever which measures about 1.5 -2kms, but all downhill. Taxi cost us10-15euros to go up and they are outside the train station on the main street. I can't imagine the cable car would take more than 10-15 minutes. The longest part would be the wait in the busy season or so I am told. Sorry, I could not help further.