How to help with depression and cutting?

Yes, you did right. Ask mom if counseling is helping sis, if not, find a fone # in county area that handles emotional issues and ask what to do. You are NOT RESPONSIBLE, your parents are. You'll find several county agencies that can and will help you. Of ALL else fails, talk to childrens protective agency. PLEASE, she could cause serious harm to herself and heartache for entire family.