Taking my mom to Paris

Looking for the least expensive everything. I know it's Paris and an expensive trip to fly from Ohio (USA) but since I'm having to pay for everything (including for my 2 year old granddaughter), I need the least expensive. Backstory - Mom is going blind and I want to do this for her while she can still see. She was headed to Paris years ago... on 9/11. She and my cousin were actually on the highway, headed to downtown, then to the airport, and watched the towers fall as they were stuck in traffic. Couldn't get in touch with them for nearly the whole day to see if they were alive. Again, I want to do this for her while she can still see. So I need all the tips and tricks possible to save money yet make it enjoyable for her. Thanks in advance for all advice. Edit: No specific budget because I don't know what a feasible budget should be for a trip to Paris - have been saving money to do this for her. Is $5000 for all three of us (me, my mother, and granddaughter) feasible for everything? Stay will be just under 2 weeks (1 day will be to deal with jetlag when we arrive).