The EDF usage definitely isn't easy to get to, but possible, Mum...
Login to your acc, go to 'Account activity', then click 'My energy graph'.
You'll finish up with a download of a CSV file if you scroll down to the link, but this is just a non-usable picture of your usage and costs.
After that, there are ways to convert CSV files to Excel, or what I do, Chrome Sheets, but for me to describe how isn't the quickest way to explain - you will, however, get to a proper spreadsheet, which you can use as you want, but they certainly don't make it easy, that's for sure!
If you use Chrome, then I'll try and take you through the process, but we'll need a whole evening, and a bottle of red each to compensate..;0)