Fiona O'Leary is the mother of five children, two of whom are on the autistic spectrum. She was a witness in the prosecution that led to the conviction of Patrick Merlehan for selling unlicensed and dangerous medicines.
This is the form on the HPRA website where anyone can report an adverse reaction for any drug of vaccine. This is the claim on Regret's GoFundMe page that their group represents 200 girls who are on 24-hour suicide watch.
There are examples here, here and here of abusive comments on social media against Fiona O'Leary in the names of Regret activists. I have contacted the people identified as having written the comments to ask if they were indeed the authors; they have not responded.