If you have the patients linked as a family you will be able to see all of their transactions and balances in the bottom right corner of the transaction window.

Choose one of the transactions and click on the credit card icon (1).  Change the amount in the pop up credit card window (2) to reflect the amount the entire family owes instead of the amount for this one transaction.  Notice in this example, the amount of $62 comes into the window.  You can see in the bottom right corner that the family balance is $104.74.  You have to enter the family balance into the field.  Then click "swipe" (3).

Once the payment is recorded, click on the blue list view button next to the posted payment.  

In this window change the payment amount (1) to reflect the correct amount for this one transaction.  And (2) copy the authorization code/transaction ID.

Go into each transaction and click on the credit card icon (1).  Click on"no swipe" (2).

Paste the authorization code/transaction ID into the correct field.  And then click "continue".  Repeat for each transaction.