The clichéd comment to make to someone about to take over from someone else who is well-known and highly regarded is to say they have big shoes to fill.
In taking over from Fr Frank Brennan as the new CEO of Catholic Social Services Australia on July 1, Dr Ursula Stephens comes to the position with very sizeable shoes of her own. At least metaphorically, even if her actual feet lean towards the daintier end of the spectrum.