  We consider a pair of quiver varieties (X;X') related by 3d mirror symmetry,
where X =T*Gr(k,n) is the cotangent bundle of the Grassmannian of k-planes of
n-dimensional space. We give formulas for the elliptic stable envelopes on both
sides. We show an existence of an equivariant elliptic cohomology class on X
$\times$ X' (the Mother function) whose restrictions to X and X' are the
elliptic stable envelopes of those varieties. This implies, that the
restriction matrices of the elliptic stable envelopes for X and X' are equal
after transposition and identification of the equivariant parameters on one
side with the K\"ahler parameters on the dual side.
