My Marmot Women's Phase 20, that I have right here in front of me purchased in 2017, claims a lower limit of 9.5F and a comfort rating of 21.7F. Real weights, it came in at 1lb 12.5oz including the Marmot stuff sack.
Women’s Phase 20
Manufacturer's temperature rating: 20° F (-6.6° C)
ponyespressoI love it. I'm 5'7" and I fit perfect. It is wide for me, but I guess that is good, I'm a side sleeper and I turn in the bag without the bag turning...plenty of room for your knees. Before I purchased this one, I had a men's/unisex bag and it was 6ft and my feet were always cold as I had too much room for me to heat up inside. Also at first I was unhappy with the fact that the women's bag weighed more...until I realized that a wms 20 is essentially a mens 10 degree bag, and those ratings seem like BS to me anyways as I sleep cold. I was warm in this bag at 39 degrees wearing Patagonia Cap4 Thermals.
Women’s Phase 20