Appropriate procedures for confidentiality

I am supporting a child in year 1 who is on the autistic spectrum and is being monitored by all staff while he settles in. I have been given information on his background and access to reports from other professionals. He is demonstrating unpredictable behaviour which has been witnessed by a parent who helps out in class. She is now speaking about it to other parents. This parent approaches me when she sees me at the local shop at the weekend and asks me where this child has come from and why he is in mainstream school. She says it is not the right place for him.
In this situation I would politely tell her that unfortunately that any information about the child is confidential and I cannot talk to her about it. I would also suggest to her that if she has any concerns she may wish to speak to the class teacher in regards to them who may be able to help her more. I would also politely ask her if she could refrain from discussing what she has seen in class with other parents as this is confidential. I would also ensure that I pass on my concerns to the class teacher in regards to her talking about the child with other parents and also about her approaching me outside of school and asking questions about the child.

Anne, a fellow teaching assistant, confides in me that she is going for an interview for a new job but asks me not to tell anyone else in school.
In this situation I would agree to keep this to myself and not tell anyone, I would also be careful about where I discussed this with Anne in case of people over