I did a B.Ed as my undergraduate degree - in the face of advice from my school not to I was bloodyminded adamant at the time that I wanted to teach. By the time I got the end of the course I realised that the academic subject side of things was not as fulfilling as I'd have liked, so I did an MA before starting my teaching career.
I didn't really have a proper uni experience as I went to teacher training college which was mostly female, and there were lots of early nights etc as we worked pretty hard.
Although I value the experience I gained of teaching and the level of my knowledge around teaching and learning, with hindsight I think it would have been better to do a degree then a PGCE. You are more likely to meet a wider mix of people and broaden your horizons before knuckling down and training to be a teacher.
Teaching is hard work, it is fatiguing to go from full-time education straight into teacher training and then straight into teaching. Better to have a few years with no classrooms in sight, I think. And of course if she changes her mind, she will have more flexibility to go in other directions at the end of a subject degree.
My views are coloured by being a SAHM now - I used to only think of it in terms of my professional development, but now I see it in terms of my personal development. And I have also known many excellent teachers who did PGCEs - they go into it with more focus and self-awareness, IMO.