The most important thing is that you're there for her, and with all the stress that she is having at work she probably really appreciates that she is not alone and has someone who really cares about her.
I'd suggest starting off by asking her what support you can give her, rather than trying to decide yourself what she needs to do. I'm going through a similar situation at the moment (not just work but also pressure from house renovation as well) and my partner is great, but does get cross as he sees me very upset and stressed and doesn't understand 'why I don't sort it out'. Unfortunately, that adds to the pressure and stress and becomes another thing that I need to be responsible for. Although many guys are very 'action-focused' and think that sympathy doens't help, for many women, and hug and an opportunity to talk without being judged is really importnat, and yes, sympathetic words can and do help by making you feel that you're not alone!
Then it gives you both a chance to talk though what might be done, breaking it down into managable 'chunks' for what to do in the short, medium and long term.
Now … I just need to pay attention to my own words as I'm currently working away on an FOI request, missing my work xmas lunch, worrying about the car that needs fixing, and the stress of having to drive in snow and ice to see family at the weekend …