DD2 would often only have one 40-minute nap per day (despite many efforts to get her to have more). I think she started having a decent nap when she was about 12 months old. Complete opposite to DD1 who would often have a two hour nap in the morning and a three hour nap in the arvo. Didn't know what had hit me

So it will happen but it may take a long time unfortunately. I eventually gave up trying so hard to get her to sleep. It wasn't worth the stress. Often she would fall asleep in the car. This is a double-edged sword though - getting out and about was important to DD1 and I, but also meant that DD2 had less of a routine which may have helped her be a better sleeper. So a bit of a Catch 22.