This sounds a bit like us
I lived with my best friend and her family while I was going through a break up and then as a single mom of a two year old. One day we joked about just becoming poly, a few days later we realized we were in love and not joking, and a month later we were a triad, raising three amazing kids together. We both stay home and take care of babies, the house, and eventual livestock. One offhand comment gave me a life I only could have dreamed of, and all six of us are better for it. Good luck.