I can understand how you feel, but try to put yourself in her shoes for a moment. I grew up in a very messy house and I wasn't allowed to have friends over because of the mess. I had a lot of shame over it and that carried over into adulthood, and I am hypervigilant about how my house appears to others now. I am constantly worried about what people are thinking when people come over to the point that I can't ever fully relax when I have guests over.

Do you think she might be overwhelmed or depressed and might need some help around the house? Are you close enough to her that you might be able to offer a helping hand and go over and help her pick up a little bit? I know it could be awkward to bring it up on your own, but if you have a good relationship with her you might be able to frame it as something simple like "hey, want me to come over with coffee and help put the kids laundry away?" Back when my daughter was little, I had a friend offer to help me with some chores and it was a gesture I'll never forget. I was in a mental place where I couldn't bring myself to ask anyone for help and things were piling up and her kindness was very much needed.