With fiddle under the chin and arm outstetched she should just be able to cup the end with her fingers. Maddie, now 7, has just gone on to a 3/4 size but she is VERY tall for her age and has long arms. She started on a 1/4 size just before her fifth birthday and moved on to the 1/2 size (Bill's in fact) when she was 6. That said in China they beleive in them all learning on a full size and I have been told that its better to have one slightly big than too small. If you've got a fiddle and she can cope with it I should let her try. she won't stay that size for long!!!