She predicted people would be astounded by it, but said the long tradition of the Catholic Church would ensure stability until a new Pope was chosen.
"And that's a whole new ball game."
Father Andrew Cranshaw from St Anthony's Church - which is a member of the ultra-conservative Pius X Society - said Benedict's resignation was an indication of the heavy burden being the head of the Catholic Church can be.
"The responsibility of such a role is very heavy, and the tensions within the church are extremely intense. For a man of his age, it is so difficult. It must have really taken its toll."
Fr Cranshaw said the society would remember Benedict as a pope who brought the society and the rest of the church closer together.
"He allowed conservatives more freedom within the church, and we were grateful for that."
He said the news of Benedict's resignation was all people were talking about within the St Anthony's community.
Fr Cranshaw said he hoped the next pope would be "faithful to the popes of the past".
"We would welcome a pope who upholds the unchanging teachings and practices of the church."
By contrast, St Mary's parishioner Vince McBride is hoping the next pope will be more progressive. He said Benedict started progressive in the 1960s but got more conservative later, and then more recently edged back to writing about the same concerns of social justice, equality and peace.
He's hoping the next pope will return to those unresolved issues of the 1960s.
It would be timely to have someone from Africa, South America or South East Asia, the active new centres of Catholicism, in the role.
He said it was sensible for Benedict to resign, because he was physically frail.
A new pope would be a new opportunity, and there were lots of clever and accomplished cardinals who could do the job.
Juliet Kojis is another St Mary's parishioner who found out about the resignation yesterday morning.
"I was somewhat surprised, given that it's been 600 years since the last pope resigned. On second thought I thought he was very courageous," she said.
Like Sister Catherine, she's hoping that Benedict has set a precedent by resigning before his health deteriorates.
The cardinals will be assembling in Rome ahead of a mid-March conclave to elect a new pope. The process involves secret ballots until they reach a consensus, and a new leader is expected by Easter.