My 10yo daughter won the lead in the play Charlotte's Web.

It's being put on by the local community theater and she won the part of Charlotte.  This is the first time she has tried out for a play and her first role.  She was so excited for the first couple of weeks and now she is becoming more and more stressed about learning her lines.  It is a two act play and she has almost all of act I down.  The first performance is April 15th.  I keep telling her she is doing great and we will just keeping working on it together.  The direct keeps telling her she is doing a great job.  Today, when we were running lines, she got so frustrated because she kept stumbling over lines that she broke down and started crying saying she was never going to learn all her lines and that she was "stressed out and shouldn't have even auditioned."  I've tried to put her mind ease by telling her that she doesn't have to get the lines perfect as long as she gets the meaning across and I've told her that if she is on stage and forgets a line, there will be someone off stage to whisper her line to her.  I told her she cannot quit because she made a committment and it is important to do what we promise to do.

Does anyone have any suggestions or strategies to make it easier and more fun for her to learn her lines?  I hate to see her so upset.  This is supposed to be fun.  I'm hoping that maybe today she is just tired and a little cranky and emotional.