Such temporary separations will give her practice in adjusting to different situations and interacting with people outside the family. Lower the pressure. Consider whether you're pushing too hard in terms of grades or chores. You can also help your child feel secure and well rested by keeping mealtimes and other routines as regular as possible. Use your sense of humor.
Laughter goes a long way towards resolving anxiety.
If your child is worrying about an upcoming piano recital, tell her the old trick of imagining the audience in their underwear. Or describe the time you bombed while making a toast at your sister's wedding. Funny stories put things in perspective, and if your child learns to laugh at herself when she occasionally flops, she'll have an easier time throughout life. Don't demand toughness. Your child already is tough, in ways you probably don't appreciate.