Emma, from Wymondham, has run the marathon in the capital twice before with a personal best time of five hours and six minutes.
“I’m aiming for four-and-a-half hours next year,” said Emma, 37, who will be supported by a group of friends cheering her on.
“I’m looking forward to the atmosphere on the day and the charity start line and the day is very emotional.
“I’m not looking forward to the cold winter runs - last year I trained in the snow!
“I swim and cycle and also do Pilates and I believe cross training really helps, not only with fitness but avoids injury.”
Emma is hoping to raise more than £1,000 for Papworth Trust which she chose as a charity because a friend’s son is disabled.