  The nuclear modification factor $R_{AA}$ of non-photonic electrons in ${Au} +
{Au}$ collisions at $\sqrt{s_{NN}^{}} = 200$ GeV is studied by considering the
decays of heavy-flavor hadrons produced in a quark coalescence model. Although
an enhanced $\Lambda_c/D^0$ ratio is predicted by the coalescence model, it is
peaked at small transverse momenta ($\sim 2$ GeV) due to the large difference
between heavy and light quark masses. As a result, the enhanced $\Lambda_c/D^0$
ratio, which is expected to suppress the electron $R_{AA}$ as the branching
ratio of $\Lambda_c$ decay into electrons is smaller than that of $D^0$, does
not lead to additional suppression of the electron $R_{AA}$ at large transverse
momenta ($\ge 5$ GeV), where the suppression is mainly due to heavy quark
energy loss in produced quark-gluon plasma. Also, the enhanced
$\Lambda_b/\bar{B}^0$ ratio predicted by the coalescence model has even smaller
effect on the non-photonic electron $R_{AA}$ as bottom baryons and mesons have
similar branching ratios for semi-leptonic decays into electrons.
