My Daughter Is Having A Panic Attack, Whereby She Has

My daughter is having a panic attack, whereby she has indicated her heart is racing and won't slow down. I checked her heartbeat and it most definitely is racing, 140-150. I have had her sit down, laydown, and talk calmly to her. she is not overly scared or irrational but recognizes her heart is racing and I also felt her chest and could physically feel her heart racing. She is a smoker and drinks but hasn't today. I gave her some water and again helped her to sit down and stop moving because she wants to move and maybe a slow pacing walk is good, looking for some helpers. Thank you