Mom is needing more and more care and we are concerned about her ability to live my herself. She has enough funds to last a short time if she self pays, how to choose an assisted living facility when we can only pay for a short time , then need to apply for assistance. Not sure how you make that transition financially when she can only pay for a short time
Sometimes families can work out a third party agreement with assisted living facilities. In other words, if the resident doesn't have quite enough in private funds to make rent for more than a few months, the family can sign an agreement to supplement the difference between the resident's monthly income and what's owed to the assisted living facility. The agreement serves to guarantee private payment for a specific amount of time and this may make the difference in being accepted for residency. I'm not saying its a fair option or even feasible for everyone, but something to keep in the back of your mind if you start running into issues getting mom placed.
Then consider whether "spending down" some or all of mother's resources would be a good idea, instead of spending it all on self-pay might be a good idea. Once she is on Medicaid she will have a very small personal allowance each month. Building up her wardrobe, buying a five-year subscription to her favorite magazines, getting new glasses and having her hearing tested, etc. would be the kind of things it would make sense to spend her money on, especially if you find a place that takes Medicaid right from the beginning.