  We study Asymmetric Dark Matter (ADM) in the context of the minimal
(Fraternal) Twin Higgs solution to the little hierarchy problem, with a twin
sector with gauged $SU(3)' \times SU(2)'$, a twin Higgs, and only third
generation twin fermions. Naturalness requires the QCD$^\prime$ scale
$\Lambda'_{\rm QCD} \simeq 0.5 - 20 \ {\rm GeV}$, and $t'$ to be heavy. We
focus on the light $b'$ quark regime, $m_{b'} \lesssim \Lambda'_{\rm QCD}$,
where QCD$^\prime$ is characterised by a single scale $\Lambda'_{\rm QCD}$ with
no light pions. A twin baryon number asymmetry leads to a successful DM
candidate: the spin-3/2 twin baryon, $\Delta' \sim b'b'b'$, with a dynamically
determined mass ($\sim 5 \Lambda'_{\rm QCD}$) in the preferred range for the
DM-to-baryon ratio $\Omega_{\rm DM}/\Omega_{\rm baryon} \simeq 5$. Gauging the
$U(1)'$ group leads to twin atoms ($\Delta'$ - $\bar {\tau'}$ bound states)
that are successful ADM candidates in significant regions of parameter space,
sometimes with observable changes to DM halo properties. Direct detection
signatures satisfy current bounds, at times modified by dark form factors.
