One minute you’re saying everything is great minus the lack of sex, yet your proceeding posts list off all her inadequacies as a wife, who you mention that you’ve been unhappy with for years.
Which is it?
Someone said on the first page that women don’t enjoy sex?? So untrue!
When you’ve had sex, is she satisfied afterwards, or do you get what you want and then roll over leaving her unsatisfied? Many (in fact most) women don’t orgasm through penetration alone. Could you imagine each time you have sex, you never get to orgasm. You’d get sick of that eventually. Is that the case for her or is she genuinely left happy afterwards?
Do you date her? Or don’t view her as a household appliance or pet, where you need to read the manual / monitor cycles to understand how the appliance/pet will operate on different days?
Have you given her the ick?
Do you still fancy one another?
Do you both do your fair share of parenting and household chores, or is there an imbalance?
Is she seeing someone else?
Does she just view you as a man child or inconsiderate sex pest?
So many questions and so many different scenarios of what could be happening, so asking random strangers on Mumsnet will not be in the slightest bit helpful. You need to ask her.
Eg I had a friend once who would not sleep with her DH anymore because she was frustrated that their entire marriage sex lasted around 20 seconds and he wouldn’t go and see a DR about his premature ejaculation. She was over getting wet and turned on for less than 30 seconds of pleasure.
I know someone else whose husband never brushed his teeth despite her nagging. She couldn’t stomach having sex with or kissing him because it made her want to vomit.
Another friend cut out having sex with her DH because she discovered his weird porn habits and felt self conscious being naked with him.
There could be a thousand different reasons she doesn’t want to sleep with you. Instead of tracking her cycle (which is fucking weird and would make my vagina clamp shut), or asking to schedule in sex, maybe ask her what’s going on. Maybe take her out for dinner without the kids with zero expectations of sex afterwards?