My sister stole my deceased mother's jewelry and won't give it back.

I am a 22 year old female and my sister (18F) is my only sibling. We both live with our father, as my mother passed away a year and a half ago.<br><br>I have an older brother, but he and I have very little contact with each other outside of maybe once or twice a year. He lives in a different state.<br><br>I have always been very close with my sister. We shared a bedroom together, went to the same school and were inseparable. We had no contact with our biological father until I was 19, as he abandoned us when I was 3.<br><br>However, our relationship started to deteriorate when our mother was sick. She was diagnosed with a rare type of cancer, but passed away a year later.<br><br>Throughout her sickness, our sister took it very badly and stopped spending time with her. I stayed with her the entire time, but she stopped going to school and became a recluse and isolated herself. This created a rift between us, as I was spending more time with her and helping take care of her.<br><br>After our mothers passing, we inherited all of her belongings and possessions. That being said, I kept her jewelry, which was left to me by my grandparents. There was a lot of it, including a diamond ring that my mother had bought for me and a gold cross necklace that my grandparents bought her.<br><br>These were the two most important pieces of jewelry I had, as they held a lot of sentimental value to me.<br><br>Fast forward a year and a half and I noticed that these two pieces were missing. I searched high and low for them and eventually asked my sister where they were. She told me that she had taken them and sold them at a pawn shop.<br><br>I was distraught and angry. I didn't understand why she would take something so precious to me, and most importantly, without asking me beforehand.<br><br>I confronted our father about this and he said that he would have a talk with her, but nothing ever came of it. A few months later, I found out that my sister had taken more of my mother's jewelry and was wearing them.<br><br>I felt betrayed and hurt. I didn't understand why she would keep doing this, even after our father talked to her about it. I felt like she was just disrespecting me and my mother's memory.<br><br>I tried to talk to her about it, but she just said that she would buy me a new ring, which is absurd. I don't want a new ring, I want the one my mother bought me.<br><br>I feel like she is just taking advantage of me and our situation. I don't know what to do.<br><br>Has anyone else dealt with a situation like this? How did you handle it? I feel like I've been pushed to the edge.<br><br>Any advice would be greatly appreciated, as I am honestly at a loss of what to do.<br><br>Edit: Thanks for all the help and advice guys. I'm honestly overwhelmed by all the comments. I didn't expect my post to get this much traction.<br><br>I'm going to get some counseling and therapy and talk to my dad about this. I'm not blaming him, as he is also grieving and I know he is doing the best he can on his part.<br><br>I don't really know what to do with some of the comments calling him a piece of garbage and a worthless father. I know he is doing his best, and he has been there for me and my sister the entire time. He is not a terrible person.<br><br>I appreciate all the comments telling me to take responsibility for my actions and to take initiative. I will do that, and I will try to be more assertive and tell my sister how I really feel.<br><br>I am mostly writing this update so I can get a few things off my mind.<br><br>You guys are honestly the best, and I am grateful for this community.<br><br>Thank you all again.