If you're anticipating Jack really enjoying the city and wanting to go back in a year or two, then stay until Wednesday. If there's a bunch of other places you'd also like to go, then maybe it'd be worth it to stay the extra day.
I apologize in advance to all our lovely, lovely NYC posters (and lurkers) but...I went to NYC once and except for regretting not visiting a couple sites, I have no big desire to go back to the Big Apple. I didn't have a lot of control over what I got to see my one and only visit; Sis' daughter was graduating from NYU, so a full day was devoted to the graduation ceremony and a celebratory dinner. Plus the second to last day of my vacation, we took the train to Poughkeepsie, where many of my BIL's relatives live, for a graduation party. I've mentioned before how we stayed overnight at BIL's one sister's house and I got stuck sleeping on the living room couch* (which wasn't a pullout) and then got yelled at by the sister the next morning when a fuse blew while I was blow drying my hair (it was supposedly somehow MY fault, though I had the dryer on the lowest setting).
* the worst part about sleeping on the couch, other than, well, sleeping on a couch, was BIL's other sister came over for the party and stayed until 1:00 AM. She and a few others were chatting in what was essentially my bedroom for the night, so I didn't get to sleep until very, very late, and we had to be up very, very early to catch the train back to NYC and then a taxi to the airport.
The only touristy things we did were Ellis Island (which I enjoyed), some museum devoted to textiles (zzzzzzz) and a walk through Little Italy. There was also a department thing that Sis and BIL went to that I skipped; I walked around Times Square instead. I wouldn't mind seeing a little more of NYC such as the Empire State Building, Central Park and the 9/11 memorial (I want to look for my one classmate's name), and I wouldn't mind enjoying more of the fabulous cuisine (niece is a vegan so we ate mostly at vegan restaurants, which for me ranged from very good to meh). And I would LOVE to go to Coney Island. But I also wouldn't mind if I never went to the city again.
Though my niece lives in NYC, and her brother is about to join her, so I wouldn't be surprised if I wound up back in the city for a family function one day...
