My wife and I made one attept, but failed due to the shoty make up of a very old jacket. If your sister in law knows what she is doing, she should be alright. I am making another attempt at altering a day jacket, but this time I am also using the Simplicity Kilt pattern to help with the cut and instructions. http://cgi.ebay.com/ws/eBayISAPI.dll...tem=8155368486

Good Luck David.