It’s all a bit murky. She denied he was her boyfriend and kept stating that he was married and they were just friends.
Yet at one point she admitted that she did have a boyfriend at the time. She never said he was the boyfriend but there was never any mention of a boyfriend before this (yet she kept reiterating that the doctor was married, so she could have easily said “I also had a boyfriend”). They also went out together a lot for dinner and days out, including a weekend together in London, which could possibly be seen as inappropriate if he was married and she has a boyfriend. They were also super flirty, as seen with the love heart emojis.
To me, it seems that it was more than just a friendship. And she slipped up saying she had a boyfriend when the prosecution was cross examining her and she was struggling to keep her story straight as he was putting pressure on her.
We will never know unless one of them admits to it of course but I would say that they at the very least had an emotional affair. Maybe she wanted more and saw her as her boyfriend?