Cor it makes me mad to hear of enthusiastic teachers being bullied out of the profession! I mentor students and I had an excellent student two years ago (seriously, she was amazing, a natural teacher, much better than my cynical self!) and we offered her a full time job while she was on placement with us, which she joyfully accepted. She left to go to her last teaching placement at another school and they were so awful to her she quit her course. Between the uni and our school we arranged for her to come back and finish the placement at our school, but after two days she quit for good, her spirit crushed and broken. Such a waste, I was gutted about what happened for ages. This country needs quality teachers, but I think some establishments have 'tall poppy syndrome' where certain people have to drag others down to make themselves feel better.
To be honest, it's not your line manager's right to have a comment on your medical appointments during pregnancy as it is something you are entitled to. I would suspect that text she accidentally sent you could be used to support a claim of pregnancy discrimination.
Annanouska, I can't believe your mentor said that to you! With the students I've mentored, it tended to be the ones with the best qualifications that needed the most support in transferring the knowledge to the pupils - because learning came easily to them, they sometimes struggled to know how to help pupils who had learning difficulties. I'm not saying that was the case with you, but all nqts need a supportive mentor to develop their practice regardless of their qualifications. Grrr I'm proper angry on your behalf!
Xx