The problem is that people keep getting given things like 4/6/8 sessions and so many people have issues that run deeply and it can take years to work slowly through childhood traumas. I have complex PTSD due to childhood traumas and other adult ones. The ones from childhood take so fucking long to work through. I mean years. Not 4 bloody sessions! And I don't feel good after individual sessions but cumulatively they definitely have made a positive impact. I'm not with a random life coach or "counsellor" (which means nothing in the U.K., - anybody can call themselves that) but a doctorate level professional who has done substantial further training throughout her career. The difference between her and "counsellors" I've had previously is night and day.
And I should add that I'm not in the U.K. now which is why this extended therapy has even been an option.
Back to your situation and I'd go as far as to say it's unethical for a counsellor who knows the limit is 4 sessions to go into anything about your childhood. There's no way of knowing if a client has had serious traumas (such as DV and maternal suicide and then being left with the previously violent parent) and no time to do anything helpful with them if they have. Far better to stay focussed on small, achievable targets and be productive. Some counsellors are "curious" though (I'm did counsellor training myself and noticed this was a feature of some students - I wasn't impressed with the majority of fellow students!).
I am STRONGLY in favour of the mental healthcare system being radically altered.
Imagine if you had something physical wrong with you and there were no GPs. So instead of going to the GP and getting referred elsewhere or treated by them, you went to someone who had done a few weekend courses in "general healthcare", possibly over a year or so, who was presented as a professional. They have no way of knowing what they don't know and you don't realise the limit of their knowledge, because you assume they're actually professionally trained and keep up to date with therapeutic advances etc. I mean in order to know what therapy would be best for you, they'd actually have to be able to diagnose/categorise your symptoms and have an idea about possible causes of them, if undisclosed.
Different therapies are definitely useful in different circumstances OP, but you need someone who knows what they're actually doing and then you also need to feel comfortable with them.
It's not you, it's not therapy per se, it's the inadequacy of the system.
In your last session(s), how about telling her you don't want to discuss the past, you need her to help you find a solution to the current problem.