Each organisation (denomination, “independent” church) has its own set of standards for behaviour, dress, acceptable terminology, etc.
Some might always address their prayers to “Father”, others to “Dear God”, "Our Father” or “Father God” for instance. And often you will find “acceptable” hackneyed expressions repeated again and again. Some churches might have prayer meetings or prayer sessions within other meetings, where each attendee is expected to pray; others not.
I happen to know a few people who do not feel comfortable about praying within groups. That does not mean that the strength of their faith is diminished – it simply means that they are private individuals. Some people prefer to remain quiet in studies as well.
In the case of Goodbook's youth pastor's wife, she may be shy. She may be a private person. She may consider her primary Christian duty to be supporting her husband in his ministry by being a super-duper wife and mother. I remember a pastor's wife who seemed to be interested only in supporting everything her husband said, and looking after her young family. She normally stayed quiet because she did not want to accidentally contradict a thought her husband had expressed or might express.
Whenever we see, or are drawn into, organisational norms and expectations and “acceptable ways to act and speak”, we should be wary. Such requirements can actually restrict a person's spiritual growth and maturity, by confining both their outlook and their openness to new, beneficial ideas from outside their immediate environment.
I suggest that Goodbook be kind to her youth pastor's wife – accept her as she is – even if she seems reticent to talk about her faith. Not everyone's Christian walk is the same. And people are often treated as outcasts in church circles (including evangelical) if they are “different”.
The wife as described is definitely “different”. She would probably welcome some support from a truly understanding friend.