Sexing help Urgent

[SIDDAS]

nn

 

[SIDDAS]

Hi I have 2 pair of Buttons both in different flights. both hens reared a chick I put the cock birds back in and all been fine for weeks then last week in one flight the hen well I think hen photo above got plucked so I quickly took out the cock bird to save it's life. the other flight with the white the chick and the silver the dad photo above were fine with my hen till today I got home from work and she died in my hands. she again was plucked. has the white chick matured and did they both attack the poor hen and killed her? I just don't know what to do now as i have the white chick and silver cock bird together and this chick on first photo is in with it's mother and is fine now since i took out the cock.