Can daughter sign the adoption deed & give the child to grandparent

I'm the maternal Grandfather/legal guardian(awarded by the Ld.Court),of my grandson(10+),& both biological parents are remarried with their's paramour & both has children again from their's remarriage,in this situations,We the grandparents willing to adopt our's Grandson(10+),in the process,ours' Daughter(biological mother) is willing to sign the "Adoption Deed" alone as both biological parents are legally divorced,is it possible for my daughter to sign the adoption deed in favor of us single handedly????????