Most mikveh attendants in the more central areas of Jerusalem have lots of experience with English-speaking women. The mikveh in Rechavia was recently renovated: Rechov HaAri 5, 02-563-2783. Please contact them for details about opening times and cost. Opening times vary based on the time of year, and cost varies based on the services required, generally in the range of 20-40 NIS.
The mikveh provides basic supplies, including towels, soap, shampoo, comb, cotton balls, nail polish remover, Q-tips, etc.
Your wife may come to the mikveh ready to immerse. She should just rinse off in the shower, comb her hair, and check her body for any chatzitzot.
B’hatzlacha!