Deployable side seat for a baby stroller

An optionally deployable side seat for a baby stroller to seat a second child, comprising:

• a frame including a seat bottom frame and a seat back frame and supporting a seat and back having a direction of child orientation, and at least one wheel supported for rotation on a lower portion of the frame and positioned, when the side seat is deployed, to contact a surface on which a baby stroller rolls, the wheel having a rolling axis generally aligned with said direction of child orientation such that the wheel rolls and advances in a movement direction perpendicular to the direction of child orientation,
• the frame having a plurality of releasable connectors extending back from a rear side of the frame and capable of securing to frame members on one side of a baby stroller, such that said direction of child orientation of the side seat is toward the one side and perpendicular to said movement direction, and
• the frame being capable of folding to a stowed configuration, having a first horizontal pivot axis at which the seat bottom frame is connected to the seat back frame such that the seat bottom frame folds up against the seat back frame for stowing, and said lower portion of the frame being pivotally connected, on a second horizontal pivot axis, to the seat bottom frame and extending downward from the seat bottom frame, with a means for retaining the lower portion of the frame in the deployed position.