The first thing you could do is just be there, give a hug let them know everything is going to be ok. My wife had a tough time and went into her own little bubble most of the time . I found that just being there, talking , listening and giving her a cuddle was what she wanted. When she started talking to me I realized that it’s not about relating and all that, she just wanted me to listen and show her that it was going to be ok and we can get through this.
At times I even used to just randomly play “eye spy” just help take her mind out of the dark place she was in . %90 of the time that worked .