Duvet cover for the kid who wont use a blanket

My little one sleeps in the coldest room in the house and does not like to be covered up except in her "blankey" which is, being a baby blanket, tiny and not very warm.  I found a crib duvet at Jysk for sale for $8. but, as I told my husband, Jysk didn't have a duvet cover in the right size so I had to make one ;).   I'm not in love with the fabric but the price was right ($7 for 3 metres) and it is soft, cozy flannel.  Here I was thinking that K. would be excited to have a new duvet and I could ease my momma guilt and cover her up every night when I go to bed but she HATES the blanket - has a fit if I try to put it in her crib with her.  J. loves it though so when we let her she piles into bed in her fleece nightie, covered with her princess sheet, princess blanket, K.'s duvet and her duvet *sigh*.