Making Up Fajr
When you miss a prayer unconsciously, you are supposed to offer it as soon as soon are conscious. It would be counted as offered on time. If you delay, you will lose the benefit of offering it on time. Only Farz prayer is the actual prayer. Sunnah or Nafl is additional prayer. There is no rule or specification of offering it or not along with the missed farz prayer. If you want to offer it you can.