  Kilonovae, one source of electromagnetic emission associated with neutron
star mergers, are powered by the decay of radioactive isotopes in the
neutron-rich merger ejecta. Models for kilonova emission consistent with the
electromagnetic counterpart to GW170817 predict characteristic abundance
patterns, determined by the relative balance of different types of material in
the outflow. Assuming the observed source is prototypical, this inferred
abundance pattern in turn must match $r$-process abundances deduced by other
means, such as what is observed in the solar system. We report on analysis
comparing the input mass-weighted elemental compositions adopted in our
radiative transfer simulations to the mass fractions of elements in the Sun, as
a practical prototype for the potentially universal abundance signature from
neutron-star mergers. We characterize the extent to which our parameter
inference results depend on our assumed composition for the dynamical and wind
ejecta and examine how the new results compare to previous work. We find that a
dynamical ejecta composition calculated using the FRDM2012 nuclear mass and
FRLDM fission models with extremely neutron-rich ejecta ($Y_{\rm{e}} = 0.035$)
along with moderately neutron-rich ($Y_{\rm e} = 0.27$) wind ejecta composition
yields a wind-to-dynamical mass ratio of $M_{\rm{w}}/M_{\rm{d}}$ = 0.47 which
best matches the observed AT2017gfo kilonova light curves while also producing
the best-matching abundance of neutron-capture elements in the solar system.
