My sister gets nosebleeds after intense breathing exercises; is it dangerous?

My sister started a guided Kapalbhati pranayama session to help with her general anxiety, but she has now had two nosebleeds during the practice. We are worried the intensity is too much for her body. Her brother is concerned that the forced, intense breathing is spiking her blood pressure or causing physical harm. Is this a known side effect, and should she immediately stop intense breathwork to manage her anxiety? Her DOB is 10th February 1998. Time: 5:30 PM. Location: Pune. Name: Anjali.