Family home evening can be a memorable time to be with your family and talk about serious gospel subjects with just your family. It can be a time to have fun together and learn to love being together. When family home evening is not like this, then the family experience can cause frustration and friction.
What can you do? Being supportive of your parents' efforts is number one. It is always right to bring your own good attitude. You may not be able to affect the attitudes of your siblings, but you can certainly not copy them. And you can set a good example, especially for younger brothers and sisters.
Be willing to help out with family home evening. You can offer to find games and skits connected to the subject that you can play if you have younger brothers and sisters. Make it fun. Or you can offer to make refreshments and perhaps get other family members to help.
Discussions over your siblings' attitudes or behaviors at family home evening should be left between your parents and them. The thing you can do best is be a good example, and you'll find the joy of having family home evening.