I get it. Her children are going through the “apparent fundamentalist phase”

) and you are wondering if you should agree with them.
They need to calm down and develop a deeper view of people and gratitude for life.
Out of love for her husband and children and what means so much to them, she has so devotedly and for so long accompanied them in all this.
Protestants and agnostics aren’t per se hypocrites, despite what you read here.
It is an exceedingly precious thing when a Protestant or an agnostic honours others’ Catholic faith to such a high degree - precious for her, precious for us all.
That makes it an exceedingly precious gift to them - the model of a deep thinking agnostic or Protestant. Which belies the dirty propaganda that her husband’s (their father’s) “friends” perhaps want to pull over on them.
I also was unutterably privileged to have a multi-perspectival upbringing and life (with minor variations).
This is an exceedingly precious plus-plus-plus for every single one of them and all around.
The one crucial point is the one point you don’t mention - is she attempting to engage in irregular “communion”?
It is most blessed to sit it out and make a “spiritual Communion”, something we don’t hear about enough.
As for answering Bible questions, she believes it enough to say she believes it. Is this a formal discernment process to enter the Church in which case she needs to take time (perhaps beyond the regulation 8 months) and discuss it in detail which is not at all the shame it is made out to be.
There is rather a lot at church and in church groups that she may participate actively in as it is. Many Protestants do, at Catholic parishes in the UK, and agnostic spouses.
We can’t make assumptions as to what others’ beliefs are.
In a prevailing atmosphere of so many Catholics not thinking through their beliefs anyway, no wonder she may be confused as to what “belief” is. She sounds exceedingly willing and sincere to me.
Belief is assent to degrees of inference (J H Newman). She sounds well advanced in her degrees of inference to me.