I would take your mum to the ER to get checked out. Better to be safe then sorry. Good luck to the 2 of the you.
Just to add, everything wen't fine after 10 minutes. No pain or discomfort. She drank a caffe, so her blood pressure now is 107/80, heart rhytm is 80.
btw, chest pressure is on left side, and also pain is in left arm only.