  The mirror twin Higgs (MTH) addresses the little hierarchy problem by
relating every Standard Model (SM) particle to a twin copy, but is in tension
with cosmological bounds on light degrees of freedom. Asymmetric reheating has
recently been proposed as a simple way to fix MTH cosmology by diluting the
twin energy density. We show that this dilution sets the stage for an
interesting freeze-in scenario where both the initial absence of dark sector
energy and the feeble coupling to the SM are motivated for reasons unrelated to
dark matter production. We give the twin photon a Stueckelberg mass and
freeze-in twin electron and positron dark matter through the kinetic mixing
portal. The kinetic mixing required to obtain the dark matter abundance is of
the loop-suppressed order expected from infrared contributions in the MTH.
