Personally, I like the rue Cler area, have stayed in three different hotels there and enjoyed each one. There is a metro station (Ecole Mliitaire) within a couple of blocks and many interesting places within very easy walking distance-for example, the Eiffel Tower. I think access to everything I'd want to see is very good from here. I've also stayed in the Latin Quarter, and the Marais and have enjoyed those areas as well. I think experiencing different districts in Paris is a good thing as each has it's own personality; I try to do that as often as possible :) Maybe, for your particular situation, two separate room bookings (as suggested by others!) is the answer. It's very hard for 3 adults to share those "standard" tiny bathrooms! I think you have gotten some good accommodation recommendations. Oh, I hope you love Paris as I do! I am so excited to be returning with my two eldest granddaughters next July!
edit to add: Sorry-I was composing before reading.....I see you have already booked a hotel-enjoy your time in Paris!!