A stroller has a frame structure with two laterally spaced apart sides. A seat is supported between the sides of the frame structure. A frame extension is provided on each side of the frame structure. Each frame extension projects rearward of the seat. The frame structure is at least collapsible laterally from a side-to-side in-use spacing between the frame extensions to a side-to-side compact spacing less than the in-use spacing between the frame extensions. A cross-brace extends between and interconnects the frame extensions. The cross-brace is selectively reconfigurable from a stiff condition to a loose condition with the frame extensions in the in-use spacing. In the stiff condition the brace maintains the in-use spacing between the frame extensions and in the loose condition the brace permits the frame extensions to collapse to the compact spacing. A cup holder can be carried on the cross-brace to be collapsible with the frame structure. A release mechanism can also be carried on the cross-brace and be actuable to release the cross-brace from the stiff condition to a loose condition, such that the plurality of parts are freely pivotable relative to one another in the loose condition.