There is a pattern in the November issue of "Crochet!" called the Rialto Raglan Cardigan that would probably fit the bill. The pattern calls for a chunky yarn , but I used a worsted weight mohair type yarn and it's coming out very nice. It is worked from the top down, sleeves added after body is done. It is roomy and opens down the front. It doesn't have any buttons. There are tassels at the top front opening that could easily be made thinner and longer to allow it to be loosely tied closed at the neck. It is sized up to 2X and is very quick and easy to make. Also, no seams. If you would like, I can rip out and mail the pattern to you when I am done as long as you pinky swear that you will send it back.

There are a bunch of bed jacket patterns for sale on this link on ebay.com:

http://shop.ebay.com/i.html?_nkw=crochet+bed+jacket+patterns&_sacat=0&_t...

Maybe one of these will work.
Char55