I would be ok with it if you told me in private and with compassion. But I would be very annoyed if you talked about it with other people without talking to me. I would see that as catty and not about my child's best interest but more like gossiping. I think you will be able to express yourself better just discussing it in person with her. After all you have personal experience with this and you are coming from a caring point of view. Good luck with it. I know it must be hard.