Fertile duck egg died instantly URGENT HELP!?

We had a broody silkie sitting on 3 small duck eggs I told my mum specifically that they were due to hatch THIS Saturday but thought I said LAST Saturday :( I left to my grandmas house just before and came bak to find my mum heart broken I asked what was wrong and she said I cracked 1 duck egg to see if it was fetile and it was she said when I cracked the egg the duck moved for a second or to then dies instantly :'( this has made ME heart broken and angry As I told her nearly 5 times they were due this Saturday she said there was a yolk attached to it is there still another chance the other eggs will be fertile she said she cracked the lightest egg cause she thought there was nothing so obviously the others are heavier do usually the lightest have babies please help as this is urgent and has left me very upset!