Quick Question About Cardio...

My lady works at our hospital and we use the gym there. However I cannot get in without her, she is currently recovering from an injury with her leg and needs to rest it. We just had dinner (maybe an hour ago) and I am feeling antsy and was wondering if it would be ok for me to do some light cardio...im talking Wii Fit. I was wondering if this is a bad idea to workout and eat basically nothing for the rest of the night.