Versailles

Of course it is possible. Trains from Paris to Versailles Rive Gauche-Chateau are frequent and inexpensive (3.65 EUR). Takes about 45 minutes, depending on where you start.

You can even download Rick's Versailles audio tour and listen to that.
https://podcasts.ricksteves.com/walkingtours/Versailles.mp3

Sam-
Thank you! Do you know if the station a hike to Versailles or is it walkable?

Danielle, I highly recommend reading the Rick Steves Paris guidebook, it is full of invaluable information about Paris and specific places, like Versailles. He explains how to get there, where to go when you’re there, where bathrooms are, eating options, all the choices of what to see there, the history. It’s very, very helpful for Paris and any place you'll want to go to. It’s even a valuable source of info for me and I grew up in Paris and I visit often for long periods of time. You can buy it here online, at a bookstore or get it from your library.

Visiting Versailles on your own is very easy, especially with Rick’s Paris guidebook explaining everything in detail.

Front gate is about 4/10 of a mile, a 10 minute walk from Rive Gauche station.

I agree with Susan .

Danielle, if it makes any difference in your walking it is a pretty easy walk, no hills. I was there 2 years ago. My sister was waiting for her knee replacement and my knee was almost ready for one and we made the walk easily. I have been there a few times and last time took the small tram train to Marie Antoinette's farm and it was the highlight of our visit.

You can also go to google maps, put Versailles as a point, navigate to it, then click on the Metro station and ask for directions (make sure you choose walking) and it will give you the route and distance (probably in KM, so you'd have to change it to Imperial).

Last month I took the RER A to Defence, and then took the Ligne U to Versailles Rive Droit (about a 20 min ride), instead of taking the RER C.

I was with my mother who had just turned eighty and had knee replacement 2 years ago. We had little problem with the walk from the station to the palace. She did fine walking around the palace. But when it was time to go, she was tired, so we decided to take a taxi. At first the guy did not want to take us, telling us that the station was very close. And it was, but when I explained about my mother knee, he gave in, but said the minimum fare was 7€, which was fine. (The actual ride would have been 6.05€.)

When the train comes above ground, there is a wonderful view of the Effeil tower as you look eastward back into the city.

We went on a Tuesday, and just out side of the station, in the Place du March Notre Dame there was a large open air market. It would make a great place to stock up if one were to have a picnic.

We went yesterday. Took the RER C from Musee D'Orsay to the Versailles-Château Rive Gauche station. Train was 33 min and walk to the Chateau was 12 minutes. We arrived around 11am and left around 6pm. This is our first trip to Paris and 5th day of the trip, and we were a bit museum'ed out, so we really enjoyed the time outdoors. The weather was gorgeous. We used the Petit Train to get around the grounds. For the Petit Train it was 8.50/adult and 6.50/youth (sorry, don't remember the age range for youth but our 14 and 16 y.o. teens were charged 6.50). It has 4 stops: Chateau, Grand Canal, Grand Trianon, Petit Trianon and they come around every 15 minutes. Apparently we still managed to walk 12 miles yesterday. The Petit Trianon was probably our favorite section, with the Grotto where you get a little lost. We did book the English tour and it was really nice to see some private rooms. It cost 10 euros per person, available to book online the night before.

Overall Paris has been very easy., with low crowds. Walked right in at almost all museums. When we went to the Musee de L'Orangerie, we didn't realized we needed to book a time slot and did it on the spot and walked in. We decided to go the Catacombs last minute, booked it on the bus ride there. Also I'm not sure why, but we've had so many friendly interactions. Friendly servers and helpful museum employees everywhere we go. One of our teens attempts to communicate in French so that must help a lot! We missed our train to Versailles so were late for our tour. Someone at the entrance went out of her way to take us to the tour office, convinced that lady to let us connect with the tour in progress, then walked us to the tour. It probably took 20 minutes of her time and she was so patient with us. We were all warned about other people's bad experiences but we've had the opposite.

We did have a couple of issues (Rodin and Musee de L'Armee) where we were told our teens had to pay for admission because only EU citizens under 26 got free admission, and I had to pull up the information for them on the museum websites. The employee asked another employee and let us through. Under 18 year olds are free at just about every museum and monument. The only place we paid for the kids was the Eiffel Tower.

Per advise from hotel, we stayed near Trocadero, took metro to end of line and when you come up there will be, or soon will be, a bus that drops you off across the street from Versailles. It was seamless!