True to his words, Jack Ogden did start to try and eradicate each member of the Parkers. Though not yet dead, they are all in critical condition.
Only Chairman John, Madam Kelly, and the twins were untouched. Living in the most secure place was an advantage for them. But that doesn't mean Jack Ogden will spare them. Jack Ogden will find a way to get his hands on them until only Jacob and J are left.
He plans on eliminating all of them and then later on finding a way to take over the Robin Hood Society. He will not rest until he does so.
If he cannot get the heiress to marry his grandson, then he will eliminate everyone in line to take over the Robin Hood Society until no one is left.