I am glad to hear that your daughter enjoys school and is involved in activities.  At 5 years old, kids want to please their parents.  They do not want to be or feel rejected.  The fact that she is involved with ballet and performs at home is very good.  Keeping her involved in activities where she will have to perform will help her anxious feelings subside.   There could be some other factors to consider:  was she feeling well? did she get enough sleep the night before?  are there other changes in the home environment?   Be sure to pre-teach expectations prior to these situations to help set her up for success.  Sometimes just gentle and kind reassurance that she can "do it with the class and be ok" can be enough.  Also, watch your behavior when she refuses to participate.  Is there anything that you may do that could reinforce this behavior from her?  Since it sounds like this seems to be a pattern for her, as parents you want to provide encouragement & help her be more independent.   Set up a chart where her ballet and home performances are on the chart.  She can earn stars or check marks.  Praise and hug her every time she earns a star or check mark.  Then at the end of the week, she can earn something from a menu of items.  The menu of items can have many items from choosing a box of cereal to what she would like for dinner that night or even what T.V. program your family will watch together.  Then when it comes to a performance at school or in a large setting, she can earn 10 to 20 stars if she is able to participate in the performance.   You can have her practice talking to adults (that you know) and have her ask them questions also.  Ask her teacher to become involved and she can earn stars or checks for those adult interactions also.  Just review with her at the end of the day how she feels she did with answering questions from the teacher as this can also teach her to be honest with you.  There may be days where she may not earn as many stars or checks as she thought, but again, reassure her that tomorrow is a new day and she can focus herself.   Some kids are more reluctant than others when it comes to “performing" in front of others. By fostering independence,  pre-teaching of skills, and with positive reinforcement you can help her change her behaviors in similar situations in the future.  Boys Town National Hotline 1-800-448-3000