Shalom, I married six years ago a man who has different Minhagim that my children and I had. At that time we decided that I would continue davening my old Nusach and going with my kids to their shul on Shabbat to supervise over them and also so as not to confuse them with a different Nusach at their father’s shul and in our home. None of my kids lives with us anymore, they married, or live independently and the youngest one moved in with their father in another city. Should I change now my Nusach to my husband’s?

Ideally a married woman will take over her husband's Nusach, if it difficult and will badly effect her Kavanah she can keep her own Nusach. (Tefilah Kehilchatah p. 88)