Have you ever put her in a wearable blanket? My son is 15 monts old and still uses one! It is a DREAM! They even make them for 'big kids' (2-3 years old).... they sell some in Babies R Us; but here's the link if you're interested. It zips from the top to the bottom, so no worries on her getting it undone; and it's very cozy and warm! We buy the Deluxe Velboa for winter, and cotton for summer. He wears a Large at 15 months and still has plenty of room to grow. When he was 6 months, we used a medium!
Good luck!
http://www.halosleep.com/product_listing.cfm?ca_id=1000