My mum helped me when my husband left just by being there, if I wanted to pop in, if I wanted to phone. I know it broke her heart to seeing me like it. Just be there, listen to her and love her. She will smile again, when she is ready, honest! The one thing that my mum did that I didn't like was make her feelings known about my now ex, which made it difficult when I still loved him. I know she was right now, but at the time just listening and hugs would have helped. You are a lovely mum for caring the way you do and between you she will come out the otherside with a smile.