I'm so sorry to hear about the loss of your mother. That must have been a terrible holiday season for you and your family. I wasn't always a good organizer, but I started organizing my office at work many years ago after taking the place of a very disorganized person and it felt so good, that I gradually started becoming more and more organized, both at work and at home. I'll give you an idea of what I would do. First I'd buy or have built, a whole wall of shelves in your sewing room. Then I'd buy some plastic bins that would stack. Then I'd start with the category that has the least amount of stuff, whether that's cross stitch, knitting, etc. and sort through everything in that category, and then find a home for it. The secret for me has been finding containers that fit the purpose. I have baskets for balls of yarn, (which fit in 2 baskets) and a bin for all the skeins (which fill one big plastic bin). If you are short of space, think vertical. Buy or build tall bookshelves, add high shelves above windows, sewing tables, etc. It's so easy to pile things up on the floor, but once you have shelves, it's easier to stay organized. I'd move a portion of the stuff into a spare bedroom and clear one end of your sewing room and start there. I would look through everything carefully, and if you think you will use it in the future, I'd put it away. But if it's not to your taste or something that you probably will never use, I'd start a bin for future donation or sale. It might be hard to give any of your mother's things away right now, but if you put stuff in a bin and look at it again in 6 months, you might feel more able to part with it. Good luck with everything! Take it slow, but work on it steadily and before you know it, it will all be organized and easier to find and use!