I hear you! I have a Miss Houdini too! I started a thread a little while ago asking for help. It's HERE if you want to read it.

The best thing that worked for us is based on a suggestion by Oorki Galoorki in that thread. I use a really long muslin wrap, fold it a little height-wise so it's just a bit longer than the length of her arms. I lie her on top of it and bring one side of the wrap up and over one of her arms, down again, tucking it underneath her body. I then do the same with the other arm. It keeps her arms strapped tightly to her side. THEN I wrap her in a cot sheet, this hold everything in place. It sounds extreme LOL, but it is the only thing that works (most of the time ).

I hope that description kind of helps. If you Google "Miracle Blanket instructions", and look at the Miracle Blanket website you will see what I mean about tucking her arms down. HTH