Timing of a new arrival is crucial for siblings and parents

It seems only months since Her Royal Highness Kate Middleton, Saturdays star Una Healy, presenter Claire Byrne and author/actress Amy Huberman made headlines with news of their first arrivals.
Now all four are expecting second babies. Prince George and Aoife Belle are set to become, respectively, a big brother and big sister next year, while Patrick and Sadie steal the march on them with younger siblings expected this year.