I am so sorry for your loss. I can't imagine your courage to do this sale so soon after your daughter's passing. Sending hugs and prayers. Your daughter must have been such a kind hearted soul to take in abused horses. She sounds like my sister.
The suggestion to hold a special quilter's sale is smart. Quilters will understand the value of fabric as well as the enormity of the work to organize such a sale efficiently. When I went to an estate sale of a quilter, the daughter had it pretty well organized. Bolts were leaning against walls or stacked not too high. Supplies were on one table. all Christmas prints were separate from the rest. juvenile prints in one section, machines in a side room. Granted, this was thru craigslist and I set up an appointment as it was 60 miles away. I was her last of many buyers. She started out measuring and cutting at the cutting table, but soon we agreed that she could use her wingspan. I didn't nickel and dime her. $2.00/yd was a steal.
I guess you need to decide if you'd rather do a little more work for more cash, or less work to get it over with ASAP with less $$.
If if it were me, I'd sell no less than 1-yard cuts off bolts. I'd price the whole bolt well so that people are motivated to carry the whole thing out.
fat quarters -- I'd group by color for easy shopping. $1 each.
thread-- spools in shallow baskets near register -- small $1 each, cones $2 each ?
Scraps-- stuffed into gallon ziplocks $1 each bag ahead of time.
Maybe be offer some sort of freebie for any purchase over $25 so that inventory moves faster. People at $22 might just buy $3 more in stuff to get something free.
Make sure you have plenty of hands on deck for logistical help, security, and moral support. I'd try a Friday andSaturday sale. Advertise well. It'll be worth the price of the ad.
I'd sell the leftovers thru the professionals. Here's to a great turnout and a successful sale. Again, my condolences.