Ash dropped hers around 18 months, for awhile tho I was able to put her in her cot for quiet time, altho she didn't sleep she would actually stay in there for 1-1.5hrs with books, then that got shorter and shorter til she'd carry on as soon as I tried.
Evenings were bit of nightmare for a little while she'd be overtired by that stage, we did move her bedtime a bit earlier too. If she gives them up maybe you could move her bedtime to 7:30ish?