The daughter idea makes me shudder. If the franchise went that way it could
become nothing more than the Lara Croft/Relic Hunter wank that it inspired.
Any stories concerning Indy's offspring would take the settings into more
contemporary times which, in my opinion, would conflict with the tone of
the originals.
A younger Indy would be the way to go. The TV series had such potential
and it needs to be rejuvinated.