😭 My fiance's bunny is missing!!!

I went to check on her and to clean her cage. Unlock the cage and she was missing. Only way she could get out was if someone let her out. I look all around the cage and yard for any signs where she might have gone or any spots the might have been dug to bury her. I didn't find anything. 😭😭😭😭 I brought her for his birthday last year. 😭😭😭😭😭 I was so piss so I still clean the cage and after I cry for a good while. My fiance suggested my mom did something since she was talking about our daughter's dog keeps trying to chase her. He thinks one of the neighbors might have took her. I don't know what to do. Maybe leave food out in her cage and maybe she'll be back? I'm just heart broken. I loved her. She desver so much love and I wish I could give it to her. I hate myself for this happening. 😭😭😭😢 My fiance idk any more he didn't seem to upset about it, but he didn't check on her for awhile.... She was more mine then his at this point. Any ideas? I feel she either out in the woods behind the fence or someone took her. 😭😭😭😭