My friends babies were big, though not quite as big as yours. Her first was 12lb2oz and 55.5cm long born vaginally with no intervention. Her second was 12lb9 and 57cm long also born vaginally with no intervention.
She was under intense pressure to induce as the Dr's beleived her PG's to be further along due to their size but she refused. She expected to have big bubs as she was 10lb and her husband was 11lb.