I lost a lot of friends when Matilda was a baby/toddler. It was awful. I think just continue to try to get together, offer her easy options for her... i.e. go to her house...

Sometimes outings or visitors are just impossible. It will mean 24 hours of screaming afterwards and sometimes thats not mentally possible, so be understanding and offer a phone call.... a night out after the kids are asleep... Something like that.

My weeks are spent with 2 appointments and running around, I don't get "time off" most weeks. So I would suggest you get her partner on board for a night out, here or there that aren't too taxing. When I'm in the thick of things, I often can't put a sentance together, I'm that brain dead.

Read some books about it. Ask her what books have helped her and ask if you can read them. If you understand it, you are a valuable friend.