Can anyone comment or advise please? I’m pretty worried about it and looking to understand what I might be at risk of catching from the incident. I feel very foolish and tbh quite scared. Any comments would be greatly appreciated.
Sorry you are so worried. You do not need to worry at all about HIV, chlamydia or gonorrhea as those are not transmitted this way. They require penetration which you say emphatically you say you didn't have. HIV is inactivated by air and this is why penetration must be part of transmission. The only way adults get HIV is from unprotected vaginal or anal sex or sharing IV drug needles.
However, rubbing of her genitals to yours does post some risk of syphilis, herpes or HPV. With syphilis, she' d have to have a sore. But the others you'd not necessarily have any signs she had them. You should test for these if you develop symptoms. With syphilis, that happens on average 3 weeks after the encounter and you can test at 6 weeks. With Herpes, symptoms can start at 2 days and beyond and you can test at 12 weeks. HPV has a wide range of strains and time frames symptoms may show. It's often symptomless.
Hope that helps.