You're right that the Trek has better low gears: 26/32 (front/back cog teeth) on the FX vs 30/26 on the FCR. I imagine that will make a big difference towing the brats uphill. However, you might be able to ask the Giant dealer if they can swap the gears for better ones for your situation/
(EDIT) The Giant Cypress DX ladies version gets close to the Trek in gearing: 28/32.