I think that as we adjust to our new life with new little ones the experience necessitates some grief work of our own, not just the children we have brought in to our home. The kids grieve the loss of language, culture, the biological parents who SHOULD have been there for them all their life and given them all their love and care--- but can't or won't. Loss of biological identity with their family, the first connections they had, etc.... (not that they know they grieve it, but they do and they will again and again and again). We grieve for them these losses too. We grieve things we don't even know we are grieving, things that this experience touches in our heart long buried. Losses we never truly grieved, things we wished for but never had, pain that was just too much, heartache, loneliness, rejection, shame. Paying attention to this and working through it is an important step to being a better parent. A parent who identifies deeply with the woundedness of the little children we now call ours. A heart that has fully grieved is a more whole heart. Not one with parts split off trying not to feel those hard feelings that we tried to bury. A parent who accepts imperfections in herself and others as an important part of the good life.
I suggest journaling. Take an hour or so a few days in a row or one day a week until you are done. Write a list of everything you feel you have lost in your life. Don't limit it to just the death of loved ones. Ideals, dreams, opportunities and hopes can be lost too. Then take each of them and write how it was lost and how you feel about it. Allow yourself to feel. Release it. Each time you do this you open your heart to your child and to a whole life.