The past week, Sunny keeps managing to get out of her sleep sack. She's 15 months old so I'm not sure if I should try another brand, or switch to blankets. I'm not convinced that she'll stay under a blanket (Her sister didn't at this age) plus I'm hoping the sleep sack will keep her from climbing out of the crib. She's such a monkey I'm sure she'll try soon.

Anyone else having this issue?