1.Line 20cm x 30cm lamington pan with plastic wrap.
2.Place jelly crystals in large heatproof jug; add the boiling water; stir until crystals are dissolved. Pour jelly into pan; refrigerate 3 hours or until set.
3.Turn jelly onto board, remove plastic; cut out 12 x 6cm stars.
4.Just before serving, place stars in glasses; gently pour in lemonade.