The Erso family, although mostly human shaped, are some form of symbiotic beings - the human form are hosts but the main organism are some alien symbionts inside.
This is how they are force-sensitive.
This symbiont nature is how Galen can manipulate the crystals.
This is also why, when their human host bodies die, the members of the Erso family survive - the symbionts get of the dead bodies eventually and take over new hosts. And at some point find each other in new lives and are reunited.
Jyn Erso, Lyra Erso, Galen Erso, symbionts
This is how they are force-sensitive.
This symbiont nature is how Galen can manipulate the crystals.
This is also why, when their human host bodies die, the members of the Erso family survive - the symbionts get of the dead bodies eventually and take over new hosts. And at some point find each other in new lives and are reunited.
Creepy alien happy ending, please.