Adoptive step mom caretaker.... kinda...
She was the caretaker of lightning when she was a child because her mom is dead while onboard lightning´s dads boat who she also got a HUGE crush for lightning´s dad along with the rest of the nation they come from.
He is pretty much a super celebrity as he is the best captain/explorer in the world, witch is a big deal for a sea merchant/pirate nation.
But they are not married or even in a real relationship by any means.
Lightning's dad and her are only in a work relationship.....for now.....
( Roland recruits her dad as his admiral after he more or less takes over the world and he ships them together in more ways then one if you know what i mean

)
In the novel this is not explained untill much later as she never actually gave away the fact she knew lighting personally when this happend.
You did get to know she knew lightning somehow but not why from her internal thoughts thought, but Roland never knew about it.
It was not until much later he finds out about lightning's dad that you get to know that they used to work together.
she is going to become Roland's number 1 trading partner for the rest of the series.