Would a name change do it?
Yes it probably would but knowing FR it will be costly and you can only do it over the phone to their 0898 premium rate number
Are you taking luggage? if not use online checkin, it costs a few quid more but means you don't have to encounter the checkin agents. If you are taking luggage try packing it all into one bag and and still check in your brother online (remember FR's luggage allowances though if you go down that route as you will be be charged excess if you go over)