A mare attacking ..defending her baby(the reason and the solution)

Good evening everybody..For some horses, they are grown up from a young age with an unqualified environment.they pass through bad circumstances where making them with a defensive impression so the horses saw that the owner or the human generally is a danger so that when a mare had a foal she will be more careful and here i want to explained how to deal with a mare when she had a foal and to understand why she adopt a defensive impression in order to avoid this impression in future. First we have to remember a sense of motherhood and every mother defend on her babies but what we will do is to drop the leash on her to send a message that we came to her not the baby after we can get her and we are able to touch her we will try to get the baby and try to craet a relationship between us besides to let them knew that we do not want to hurt her or her baby .