Caryn,
Options near the Museum of Science and Industry are a little tough. The closest places (among those discussed often here on the LTH Forum) that I have marked on my own map are Barbara Ann's (BBQ) and Lagniappe (creole, cajun), neither of which might appeal to The Picky One. But also fairly close are some very good pizza options: Candlelite (7200 S Western Ave), Vito & Nick's (8433 S Pulaski Rd), and also Top-Notch Burgers (2116 W 95th St) and right by that, The Original Rainbow Cone (9233 S. Western) for dessert.
Along/near I-55 on your way home are Nick's Tavern in Lemont (221 Main Street) for burgers, and Pappadeux Seafood Kitchen in Westmont (921 Pasquinelli Dr), to name a few. Ah, and there's the famous chicken place in Lemont too, which I ought to have on my map but don't ... I found it:
White Fence Farm. Looks to me to be very kid friendly. Petting zoo and all.
What was the other question? Right, dinner near O'Hare. Options there are more plentiful; perhaps others will jump in; I'll check my map.
This link might be helpful too.Targeted at places one might go to during a -6-hr-or-so layover at O'Hare, it does mention several good nearby dining options.
I didn't check on any of the above being open or not on Monday the 5th; given the holiday, you'd better check first. I didn't post the phone #s, but searching the names here on LTH will take you to threads for each with addresses and phone numbers.
Katie
"Your swimming suit matches your eyes, you hold your nose before diving, loving you has made me bananas!"