I would tell her to contact Professor Tim Spector of the Zoe app which is collecting data on 4 million of us. All recording daily symptoms pre and post vaccinations, batch numbers etc. Apart from the extremely small number with blood clots, now recovered, and even fewer fatalities, no long term effects recorded. I imagine it is the clots your son's girlfriend is worried about, but if she is in contact with patients her risk of catching it or giving it to them is hundreds times greater. You can always find badly done research papers as well as good ones to back up your worries! ?
Life is a risk, the cable car tragedy recently was so sad for the families, but it wouldn't stop me going in a cable car ever again.