  We study the edges of fractional quantum spin Hall insulators (FQSH) with
half-integer spin Hall conductance. These states can be viewed as symmetric
combinations of a spin-up and spin-down half-integer fractional quantum Hall
state (FQH) that are time-reversal invariant, and conserve the z-component of
spin. We consider the non-Abelian states based on the Pfaffian, anti-Pfaffian,
PH-Pfaffian, and 221 FQH, and generic Abelian FQH. For strong enough
spin-conserving interactions, we find that all the non-Abelian and Abelian
edges flow to the same fixed point that consists of a single pair of charged
counter-propagating bosonic modes. If spin-conservation is broken, the Abelian
edge can be fully gapped in a time-reversal symmetric fashion. The non-Abelian
edge with broken spin-conservation remains gapless due to time-reversal
symmetry, and can flow to a new fixed point with a helical gapless pair of
Majorana fermions. We discuss the possible relevance of our results to the
recent observation of a half-integer edge conductance in twisted MoTe2.
