MB angry because I gave NK a capri sun.

NK doesn't drink much and needs to be constantly told to drink sometimes. She wanted a capri sun from the fridge after I gave her a yoghurt and she drank it all. It was also a very hot day. MB came home and asked if I had the capri sun. I said no, NK did and she got annoyed with me and said next time don't do that and to text her first. The following day I did text her and asked if it is okay for me to give NK a capri sun and MB said "probably not" so I didn't do it and had to constantly make NK drink her plain water that she takes the tiniest sips off. Why is the capri sun even at home then???

UK capri sun is sugar free and has stevia and only naturally occurring sugars from the diluted OJ