Sister Anna-Marie and Sister Valery at the Dominican Sisters' house
The future of four Catholic orders in Cambridge is in doubt, because no new nuns have joined since the 1980s.
Sister Gemma Simmonds is a lecturer and from the Congregation of Jesus, which set up, but no longer runs, the Cambridge girls' school, St Mary's.
She does not believe there is a crisis of vocation and said: "I meet women all the time who are thinking they want to give their lives to God."
She added: "The crisis is not in vocation. The crisis is in culture."
"I think that religious communities, if they want to have new recruits, have to be willing and open to the possibility of change and challenge."
There are four Roman Catholic orders of nuns in Cambridge. They are the Dominicans at Blackfriars, the Dominican Sisters, the Congregation of Jesus, and the Sisters of the Holy Family.
All four orders live in a similar way. The nuns share a house, and the running costs are met by pooling their wages or pensions into a communal pot.
Sisters Anna-Marie and Valery are Dominican Sisters, and have known each other for nearly 50 years because they started as novitiates at the same time.
"I think we enjoyed ourselves very much in our first years," said Sister Anna-Marie. "Of course it was a different world. The prayer was all in Latin so we had to make sure our Latin was up to standard. We had to learn how to sing plainsong and perform adequately.
"So we had classes in chant, classes in Latin and so on, which wouldn't be so urgent today."
Sister Valery believes there are advantages and disadvantages to the dwindling numbers of nuns: "Being fewer has meant we can't live so institutionally as we used to do, as there aren't the numbers to run things.
"I think there are disadvantages to it. We would very much like to have more sisters. We could run our schools better, for example, and our nursing homes.
"At the same time I think the smaller numbers have helped us to build friendship more than before."
There are now only three nuns living at the Dominican Sisters' house in Cambridge. They sometimes take in foreign students to help with funds and also host nuns from abroad.
Yorkshire woman Mary Ward is now on the path to sainthood
The Congregation of Jesus was set up 400 years ago by a Yorkshire woman, Mary Ward. It was a pioneering organisation which was rejected by the Catholic church of its time.
In 1631, Pope Urban VIII described her sisters as 'poisonous growths in the Church of God (which) must be torn up from the roots'.
Pope Benedict XVI has a different view. He has declared her to be 'venerable', the first step on the path to canonisation.
Mary Ward had a completely fresh vision. She wanted her nuns to work out in the world, and not be hidden behind cloister walls. Her inspiration was the male Society of Jesus.
Sister Gemma Simmonds lives this life. She has never worn a habit and is a lecturer at Heythrop College in London. She is also a volunteer prison chaplain.
Since joining the Congregation of Jesus as an 18-year-old in the 1970s, she has worked with women and street children in Brazil and as a chaplain in the University of Cambridge.
Time for change
Sister Gemma is confident that there is a future for nuns in the 21st Century, but feels the existing orders must adapt to changes in society.
She is keenly aware that very few women nowadays feel called to a religious life in their teens.
"The days when a dozen fresh-faced 18 year olds turned up at the door are long gone," she explained. "And the people who come now have got complicated histories.
"They are people who have perhaps had relationship histories, histories within their families, work histories - experience that people like me had not remotely had when we first entered religious life."
The Catholic church provides help for people who wish to explore their vocation. There is a programme called Compass, open to men and women, which helps people to discern if this is the journey for them.
Sister Gemma believes change is inevitable if the orders are to survive: "The community is going to be smaller. I think there will be much more collaborative work and possibly even collaborative communities between members of different religious orders, possibly men and women living together and working together.
"We need to be open to change, and if that means we have to start newer, smaller communities, where new recruits come and live with sisters who are willing and able to adapt, well that is how it has to be."
Message to Pope
Sister Anna-Marie and Sister Valery at prayer in the Cambridge chapel
Sister Gemma also wants the Catholic church to become more inclusive of women.
With Pope Benedict XVI due to visit the UK in September 2010, her message to him is: "Create a space in the church for women to develop their full potential.
"This isn't saying that every woman is demanding to be ordained in the Catholic church because that's not the case, but there is a need for a greater space in the church for women to be involved in the decision-making processes in the church.
"I think the thing that does put off young, vibrant Catholic women is the sense that there is such a limited space in the Catholic church out of which they can operate."
She firmly believes that if women had played a larger role in the church, the scandalous cover-up of child abuse over the decades would not have occurred: "I don't just mean religious women, I mean mothers of families, I mean wives.
"This is where I think we can, without doing any damage to the current theological thinking, create spaces for the voices and the experiences of women to count more than they do."
'Go for it'
Sister Gemma is enthusiastic about her life as a nun: "My older sister often says to me she's jealous because she says I get to travel a lot. She says, 'Become a nun, see the world', and it's true that religious life has given me all sorts of wonderful opportunities that I would never have had outside religious life.
"Whatever happens, if you want to be bored, don't become a nun!"
Sister Gemma Simmonds' order does not wear a traditional nun's habit
She has this message for any woman thinking about the life: "Go for it. Get in touch with someone, get in touch with me, get in touch with the Compass programme, get in touch with a nun or a priest.
"And if you don't know anyone, then go on the internet and look up the Catholic church. This is a way of life that needs a lot of strength, needs a lot of imagination, needs a lot of courage, but it's a life that's enormously satisfying and it could be a way of life which makes you happier than you could have imagined being."
Not that retirement is an option.
Sister Hazel also lives in Cambridge. She was one of Sister Gemma's teachers when she began school at St Mary's.
"I still do voluntary work with people who are bereaved. On the whole, I listen to them," said Sister Hazel. "I'm 76. We don't stop when we get older."