Vehicle-mountable child safety seat assembly

A vehicle-mountable child safety seat assembly, the seat assembly including a safety seat, and a prop assembly mounted with respect to the safety seat, the prop assembly having a stowed position and a safely deployed position, the prop assembly including:

• a leg assembly;
• a foot assembly mounted to the leg assembly;
• and
• a first sensor for sensing when the prop assembly is not in the stowed position;
• a second sensor for sensing when the prop assembly is not in the safely deployed position;
• a visual warning indicator, the visual warning indicator visually obscured when the prop assembly is in the safely deployed position;
• and
• a warning system having a standby state, a timing state and a warning state,
• wherein the warning system changes from the standby state to the timing state when the first sensor senses that the prop assembly is not in its stowed position, and
• wherein the warning system changes from the timing state to the warning state, if the second sensor senses that the prop assembly is not in its safely deployed position by a pre-determined time after the change from the standby state to the timing state.