Royals usually don’t do engagements on the same day so the journalists don’t have to choose where to go and leave a less popular royal without a coverage. She had a perfect opportunity to go there without anybody’s knowledge, William and Kate were in Cyprus, Harry had some patronage meeting, there was nobody who could stop her, heck, Harry probably even encouraged her to go. She has no opportunity to merch lately and if the RF won’t give her any engagements, she’ll find them on her own