How long can a woman be without sex period?

[mjc50]

This ? is for women only please, Im 40 she is 37 we have 2 kids I as man am really affectionate and like to think Im romantic to an extent.We do dinner and a movie , but that's not enough for me , also walk on the beach at night with a bottle of wine and strawberries and sit and look at the stars and talk. We have gone dancing maybe 1 a month when we get a sitter , jog together ,we have ran a 5 k together several times .So my ? is what am I doing wrong , I ve talk to her but she says no not know