Hi, I have a 27 year old sister who is a emotional drain on my family and she clearly has no intention of leaving the house. I really wish she would go away, is there anything I can do to get rid her?

How long has she been living there? That makes a big difference. If she has been living there long enough to have that be her legal residency then you will have to formally evict her.

Whose house is it ? If it is your house you will have to give her legal notice to move and if she does not, evict her. Is it your parents home ? They will have to evict.