My 6 year old daughter i caught peeing into a play cup in her room? is this normal?

Is she re-enacting : giving a urine specimen in her pediatrician's office or a lab? An emotional reaction or negative attention from you would've reinforced the behavior & made it difficult for her to answer honestly, even if you calmly asked, " Why?". If so, calmly tell her that "peeing in a cup"is always done while sitting on the toilet & ask if she'd like paper cups in the bathroom.If it persists, see pediatrician.