Good read, old post or not. Thought I'd share my experience.
I have always lived by myself but last March moved in with my girlfriend. Right off the bat we agreed to split everything down the middle, rent, groceries, we'd each have an equal $ amount for bills in our names (3 or so each), and I said I'd even split her (now our!) dog's expenses. I made roughly 10k more than her and would pick up extra groceries, pay whenever we went out, pick up gas in her car, etc.
Just recently she has switched teaching jobs to somewhere where she will be much better off 5 years from now, but now makes ~20k less than me. She couldn't decicde at first because she was so worried about finances (our goal was to begin house-hunting in mid-2019). She flat-out asked me if I could take on more of rent since I'll be making so much more. I hadn't even thought about it since April, but of course I said sure. I have my own CC debt black hole that I am paying down, and this will put ME further back for awhile, but will allow US to live more comfortably. When those "I's" become "we's" it tends to make everything so much easier. So we pushed our collective goal of home ownership out a couple years, big deal.
Communication up front is the key.
Hey, pizza! I feel relieved for your friend! I remember reading your thread back when you started it, and kind of followed for awhile. I am so glad everything worked out for her.