Hi, I hope I can offer some assistance with your question.
I am a work psychologist and therapist and so will answer your question from this perspective.
As she has been open and honest with you as far as you can see at the moment, it would seem reasonable to take what she has said at face value.
However, there is much that can be gained from reading between the lines. You have shared an enjoyable week together, however you have still only known her for a week, so I think it is important that you keep this in due perspective. It has also been a bit of a whirlwind by the sounds of it, and there can be many reasons for people making these sorts of intense emotional connections, such as their needs, state of mind, vulnerability etc. I would also consider her mention of 'the lad she was seeing's drug problem', and her reference to him helping her do this before, which could be taken as him helping her with a drug problem before, which would certainly raise alarm bells for most people, and would indicate there may be a pattern of addiction, and all that would go with this. This can often lead to unstable, unpredictable, intense, and unsatisfying relationships, and so at this stage would be something to seriously consider whether this is an area you would want to pursue at the moment.
I hope that gives you some other perspectives to consider in terms of what feels and would be right for you at the moment.
Please let me know if I can offer any further assistance. If you are satisfied with my response, please provide a positive rating.