how many other sleeps does she have during the day? trust your instincts hun, if you think she might be ready to drop one sleep then try it for a day or two. If you can get her to bed earlier at the end of the day and she seems to be handling it ok then she probably is happy with having only 2 (I assume atm she is having 3 sleeps?) sleeps. If it just makes things worse you can always go back to adding the extra sleep. I think it was around 6 months DD dropped back to 2 sleeps, then dropped back to one sleep by about 10/11 months

Had to lol at the image of your DH dancing around to Lady Gaga with her..bet you would need your poker face for that one