Over the past couple of days, my daughter has been falling asleep in…

Over the past couple of days, my daughter has been falling asleep in daytime naps on her own, without rocking or soothing. As she gets tired, I put her down and she looks calmly at one point for a while before falling asleep. Is this normal? A growth spurt or should I be worried about something? She's not hanging from my chest like she used to.