S just turned 9 months. She's on a 2 naps schedule from before 7 months, her A times are 3;30 h and 4 h. things were are going great for about 2 weeks meaning she no longer wakes during the night. But...in the past 3-4 days, she resists sleep at bedtime, so instead of falling asleep at 9, it's now 9:30 or even 10. she just stays with her eyes closed, seems really sleepy but won't fall asleep. (she falls asleep in my arms, while i walk her across the room). so...what's the deal with this behaviour? thanks !