My DD started that at around the same age, she wouldn't sleep ANYWHERE else through the day, nights were a little different for some reason though.

In the end I nursed her until she got too big and I got sick of being sore, I am thinking it was somewhere between 7-9 months? Honestly cannot remember.

ANyway one day I rang the ABA because she was literally attached to my breast for the entire nap (so it wasn't just she wouldn't sleep anywhere else either) and I was begining to go stir crazy and she said whatever it was I did at night do through the day too so I basically did our night routine through the day and it worked ..... I put her down in her cot and she slept 2.5 hours.

Maybe somethign just clicked in her brain who knows, but I CAN tell you started doing that at around the same age your LO is now.

Best of luck hun x x

Nae x