how do i remove this family ?

Try -
Go to her Profile
Click Edit Profile
Click "Relationships" towards the top of the Edit Screen
Click the little Box to the right of that marriage (under "Remove")
Then click Remove
Then Click "Save & Close"

If the system warns you it will split the tree, but allows you to do it, do it
If the system warns you it will split the tree, and does not allow you to do it, post a request here: https://www.geni.com/discussions/245980 (give info and link you posted here, and also that the system will not allow you to remove the marriage relationship)

I will, however i contacted Yitzchak Katz ( Marc) in London and am waiting for a response before removing her. Thank you :)