Hello FancyNancyCody,
Take a look at the deck plans:
Conquest Deck plans
From my point of view, I would definitely NOT call that "near" an elevator. IMHO that's still kind of far, even from the closest elevator bank, the forward one. Which is NOT what I would choose for you. If I were trying to put you in a cabin "near an elevator" because of your knees, I'd try for something near the mid ship elevators, not the forward ones. (Example 1350 or 2358).
And short of putting you near the mid ship elevators, the aft elevator bank would be preferable to the forward one. The forward elevators are only near the theater, which you may likely visit only once per day. Where as the aft elevator bank is near the aft dining room, the aft lounge, almost all the bars that have nightly entertainment, and the lido buffet, and the aft pool.
Actually being near those aft elevators is probably your best choice, as the mid-ship elevators are still half a ship away from most things, being near only the mid-ship dining room, the mid-ship pool, and the casino.
Good luck.