doesn't have to be BFC related, but it can be was thinking of a comedy duo, so maybe Richards and Wright
Left and Right. If one dies, you've still got one Left or if the other dies what remains is All Right. If both die, you've got a glass receptacle useful for arranging coloured pebbles.
btt - 'Pete and Steve' suggested by Tykesmad leading the way at the moment come on Panda there's been no ideas from you yet will definately be using a name suggested on here, I know it's not a child but still... 'Liz and Stevie' a definate possibility