It sounds like you really want to be the great grandma but new parents can seem almost threatened by someone stepping in. They may be self conscious about this new arrival. There are all kinds of reasons for why they refused your help that do not mean that they don't want you there. They may be overwhelmed and don't want to look incompetent. They could feel that they will be asking too much. Don't assume that don't want you to be part of caring for the baby. When they have gotten used to caring for a baby you can approach them by disclosing your feelings that you feel unappreciated and left out. This should be particular to your son since your relationship is with him. You may find that he is more receptive than. You can discuss this problem with them but it may take some patience. Right now you don't know that they don't want your help. I think if you are patient you may feel more included.
Please press accept; this is the only way I am compensated