My Sister And I Are On Vacation. She Is 79.

My sister and I are on vacation. She is 79. Her face has flushed a purplish red color. She took all her medication this morning, including her BP medication. Should I be concerned about this strange color? In addition, one leg/foot is swollen with red large spots going up her leg from her ankle. I thought that discoloration was the result of water retention in swollen tissues.
I am concerned about a stroke, which seems to run in our family.
Thank you.