You must try to persuade your wife to get some help. My daughter in law suffered with PND and it was just awful. She was completely irrational and felt depressed and worthless. She ended up on anti-depressants and we had to constantly reassure her that she was doing a good job.
Your wife must be still under the watch of a health visitor or midwife. I know you cannot discuss her business with her medical professionals but I am sure if you went to see your GP and explained the situation then he/she could have a word in someone''s ear to check her out.
It seems so very sad when the children are so little and it must be absolutely awful for you.
It is devastating poor little babies dont know whats happening. She said she tried to phone health visitor but go no answer but said she left a message. lucky im on annual leave but im dreading going back to work