how to deal with gossip in family dynamics when caregiving?

I was recently talking with another caregiver who is in a different phase of her caregiving and she has now reconciled with her sibling who admitted that she previously gossiped and criticized her sister's caregiving out of guilt of not being able to help. I feel like the same thing is currently happening with my sister who gossips, criticizes, and does smear campaigns against me who has been caregiving in home for my parents for 5 years+ asking for help so I can focus on myself. Others in my family has confessed she does this. I'm already exhausted, isolated, and running out of hope. I try to ignore it and have distanced myself from those in my family who I know are involved.

Any advice on how to manage?