What happens next?

How to ignore your sister or brother 
Establish why you want to ignore your sibling. 
There are many different reasons you may want to ignore your brother or sister. 
If you're simply busy and need to focus, be sure to explain that to your sibling and make it clear you aren't ignoring your sibling out of anger.
If your sibling is doing something annoying, first ask your sibling to stop. If your sibling has done something seriously wrong to you, try to first resolve the conflict.