How can I help my friend through the loss of her cat?

My best friend who is 17 (I'm 19) had her cat, Jess, since she was 6 months old. I got a phone call from my friend today, she was in tears, her Mum had taken Jess and had her put to sleep (she was obviously very old and hadn't been well) but she didn't tell my friend that Jess was going to be put to sleep (I'm very surprised that my friend's mum did this, in my opinion it's a very cruel thing to do), so now my friend is distraught that she never got to say goodbye, and she doesn't have any photos of Jess either. I kind of know how she feels as, when i was her age, my cat that I'd had my whole life too was put to sleep, however I was the one who made the decision to have her put down, I have lots of photos and I got to say goodbye. I know the usual "She had a good life", "She knew you loved her", "she's not in pain anymore", but what else can I do? I've never seen her this upset before and I really want to help her through it as I know the loss of a pet is devastating, especially when you've had that pet your whole life and you never get to say goodbye. Hope you can help. Thanks.