Hi, Doc! My Name Is Anna. I Would Like To

Hi, doc! My name is anna. I would like to ask with regard to my daughters' behavior. Since bipolar disorder can be diagnosed at the age of 15-24 yrs old, how can I tell if my daughter has this kind of condition since she is still 5yrs old but she expresses the exact signs like this minute, she is happy , elated and anytime sooner, she turned grumpy and will have tantrums and kept on whinning. I don't know what to do.