My Mate Is 67 Years Old . Her Left Leg

My mate is 67 years old . Her left leg is swollen at the ankle. It was swollen last night and I had her elevate it when she went to bed. It started out fine this morning, but it stared to swell after she was up for a while. She elevated it again this afternoon. She says there is no pain at the ankle, but there is pain in the groin area when she walks. It feels like a pull. ?