Will you have luggage to wait for? I hope not. I travel light with a carryon and a backpack, and I can usually make it to my hotel on 57th in less than 75 minutes from JFK. I've kept detailed notes on my phone as to the times I've landed (SJC or SFO to JFK), boarded the AirTrain, loaded my Metrocard, walked onto the subway, and arrived at my hotel. Landing at JFK at 5:00 would be fine for an 8:00 PM show if the flight is on time or not too late. Most times, I find that the plane will arrive 15-30 minutes early.
However, I arrive on weekdays when I know that the subway is running on a normal schedule. Weekends, they are constantly doing maintenance and the trains are not always running as regularly. Also, if you don't already have AirTrain/Metrocards, you will need to stand in line at the machines and purchase them, which is usually quite a scene with many tourists trying to figure it out. Whenever I leave NY, I make sure that I have enough money loaded onto my Metrocard so that I don't have to stop and load it when I get off of the AirTrain.
I just learned that you can buy a 10-trip AirTrain card that is good for up to 4 people. It is 50% off the normal price of each one-way trip. What a deal! Anyhow, you could buy one and use it for the 3 of you. Read up on it online to make sure, but that is what I determined from my research. I bought one for my next trip to see how it works. It's only $25 for one and if you are headed back to JFK on your way home, you would use up 6 one-way trips which would normally be $30. So, even if you never use the card again, you will have saved $5. I think there is a way to share pay-as-you-go Metrocards for the subway, too, but I haven't researched that much since I travel alone. But I highly recommend a 7-day subway pass for each of you if you will be using the subway a lot.
Since there are three of you, maybe you just want to take a taxi or rideshare to avoid all of this, but sometimes the taxi line can be long outside.
I use the free app, CityMapper, constantly, and it has never once let me down. When you land, you can enter where you want to go, and it will list all the available options, including walking (ha ha), Uber, Lyft, public transit, taxi, buses...and it lists the prices, too, and what direction you need to walk. Seriously, it is a great app for navigating!
Have fun! Figuring out this part of it is part of the fun!