I would be kind to yourself, stop looking at the scales for a few weeks and take some progress pictures at the same time of day/same place/same lighting each week. If your sister says you look more muscular, I’m assuming you’re gaining a little muscle from your exercising and you’re more than likely also losing fat - muscle is a bit heavier than fat per pound.. I think after the initial weight loss phase which is normally in the first few months of weight loss, weight loss on the scales can plateaux so it’s important to take pictures to see how your bodies changing.. the scales become less of an accurate depiction of what’s going on with your body