Sudden weakness in 95 Y/O Mom's legs?

Here's the scenario:
Mom is 95.9 years old. Has vascular dementia from a left MCA stroke 2-1/2 years ago. She lives in a NH but does well as far as walking, toileting, etc. Her speech is poor from the stroke but I can usually make out what she's trying to say. I take her out every Saturday and Sunday. She has always been able to get in and out of the car with some assistance. She also holds her bladder very well but likes to wear protection just in case. Her appetite is not what it used to be but I believe that's normal.
Anyway...Took her to my house on Saturday. She got in and out of car as usual. Had a light lunch of grilled cheese and soup, and used the bathroom without incident.
Fast forward to Sunday. What a total difference! Getting in the car was extremely difficult and getting out was even worse! It seemed her legs got very weak all of a sudden. Getting her up off the chair was also difficult and she even fell backwards back into the chair. When she got to the bathroom she was soaked like a baby who slept through the night! She is also displaying difficulty moving her feet. It's like she can't pick them up. She didn't eat at all and I had made spaghetti and meatballs, a favorite of hers. She just drank some chocolate milk. She also did a lot of snoozing on and off all afternoon which is a bit unusual. Otherwise her mood was good. I did notice her speech was worse and one eye was more closed than usual. She also had a cough and sounded a bit congested. I'm SURE she does not have a cold or the flu.
My question is; what caused such a sudden change in her walking and her continence from one day to the next? I'm guessing mini strokes?
Any input would be appreciated.
Thank you!