The best way is to continue sending her off to bed by herself. Assure her if she wakes, she is welcome to come to you and her father. However, (this is the magic part), she won't be allowed in your bed. Keep a throw rug next to your bed and a small blanket on afghan to throw over her. She is welcome to sleep there. Even offer your hand. I used to dangle it down grasping them. This is comforting to them. I can guarantee after about a month, she won't be waking to come into your room. She won't much care for the floor and will prefer her own bed. Watch and see. No tears. No middle of the night forcing her back. Don't be surprised during a bad storm to see her return but to her place...that little rug!!
Really the only way is to be firm and consistant, she knows you will give way under pressure so she keeps it up, once you begin to say firmly no and dont engage in any arguments , she will get it, that you mean it, at the moment the mixed messages are telling her the opposite. So be firm ,yes she will wail and feel sick, and be thirsty, hungry all kinds of excuses, but quietly she goes back to her room ,after a few nights she will get it.Or like many others you have the family bed ...