My Mother Went To ER 2 Days Ago For Very

My mother went to ER 2 days ago for very bad bruised caused by car door hitting leg. It was large with a bump on top. Ice was used and then pressure bandage applied. Went home kept foot elevated and saw improvement . Calls tonight to say it was hurting-like a burning pinch. She was on her feet more this evening doing some household things. She has been almost immobile for 2 days trying to keep her leg elevated. She is 90 and on Warfarin. The bruise was not getting bigger. Are these symptoms cause for alarm?