Have never used the keel to vent spacing, easier IMO to find the pelvic points.I checked the link. I've been looking at the pubic to breast distance which for her there's plenty. I'll check the pelvic distance tmrw. I did notice she seems quite fleshy in that area. Don't know if that's a good sign, a breed thing or something else.
"Fleshy'" could be fat? That can inhibit laying.