That's a toughie! But what a pleasant decision to be making.
1000+ square feet, washer/dryer, jacuzzi, full kitchen, lovely pastel decor, privacy for you in the bedroom (and for Mom in the living room), very relaxing
OR
400+ square feet, two queens and daybed, 10 minute walk to MK or monorail ride that could take 15 minutes
I'm no help -- both choices are wonderful. We've stayed at both and love the peacefulness and SPACE of a 1 BR at OKW, but we don't spend much time at the parks. Mom may decide to just sleep on the sofa without opening it up.
If you don't have a car, some people find it a bit less convenient to be at OKW because it's so spread out, especially if you want to eat in different places at night. But others ask to be close to the main building and restaurant and don't see this as any problem. The CR has easy access to WL, Poly, and GF for meal choices.
Good luck and have a great trip!