The business is the LLC. That didn't change.
Part of the year it was taxed as a partnership and part of the year as SP.
Nothing was dissolved. The business can continue on with the same bank account. Unless they actually took all the money out of the bank account, BS should show the balance of the account.
I would probably show his ending ownership at 0% and hers at 100%, but I don't know that it really matters.
1065 return is a final since one owner no longer allows LLC to be taxed as partnership. Since it's the final 1065 return, K-1's are also final.