To set discounts for Sibling, please follow this guide.
How it works:
Firstly, DO NOT generate any invoices for the siblings. Setting discounts is for the invoices generated to know how much to generate. If you've already generated the invoices, please delete them before you continue.
1. Set the siblings
First you'll need to set the siblings in the database. Please see this guide to see how to set the the siblings.
Once you've done that, go to Students > Manage Siblings, then below the search form.
Now you will create siblign discount sets to apply to siblings. You can have a single set or multiple sets. E.g. you can have a set called "Default Siblings" and another called "3rd Free". In this example, you woud add sets on the first form. In short title you would type "Default Siblings" and for the 1st Sibling you can for example have no discount, leave that as zero. For the 2nd sibling you can have 25% off so you would deduct 25% and for the 3rd and 4th sibling you can add 10% deduction. Then you would click "Save Sibling Discount".
At this point you've only added the default set. It's not been applied to any sibling.
You can then create the next set called "3rd Free" and add the short title as "3rd Free" and for example the first sibling would have 10% off, then 2nd can also have 10% off, and the 3rd and 4th sibling would have 100% off.
2. Assign Sibling Discounts
You can now scroll down to "Siblings List & Adjustments Check"
Under each sibling group there is an adjustment you can select and apply.
This will add the Fees Adjustment according to the discount set
3. How to Delete Adjustment
Go to Fees > Fees Adjustments
Delete or edit whichever adjustment you want
the "Sibling Discount Page" is only to set the adjustments, not manage them. To manage then you would need to go Fees > Fees Adjustments.