You can try to make something special for her (best is to make it with her together) to bring to school such as a heart drawing, an note with mom and dad's love, a family picture that is wrapped in a special paper and tell her you are always with her and thinking about her while she is in school and if he misses mom and dad or scared just take look this special item...Sometimes, small kids find that is a great way finding comfort. I hope this will help a little. Also, you can try to find related kids story books from your local library and read them to her.
Best luck to you and you little girl!
