Depends entirely on what type of girl she is, some will be in the library four nights a week taking sandwiches with them and others will be going out 4 nights a week, buying new clothes and eating kebabs after two bottles of wine and 10 double vodka lemonades.
My group of friends in first year were from a variety of backgrounds, from single mothers on benefits to absolute multai. I was fortunate enough to fund myself through poker and live in catered accommodation - only food expenses were takeaways at 2am, an abundance of Asda pizzas and food on nights out really. Away from that my spending was quite ridiculous for a student thanks to poker.
The first four weeks will be far above the norm though with all events forced onto you, you can't say no and it's imperative you don't. Fancy dress costumes etc are a one off
Once those four weeks are over things calm down a lot as should spending.
The first few weeks of every term are a bit hectic though as everyone's loans come in, and towards the end of terms they become skint and spending as a whole stops.
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For an average student £50 a week after food expenses was plenty, trip to cinema and a night/two out.
- Frozen chicken breasts, frozen veg, pasta, tuna etc are all cheap and keep for a long time and are easy to cook/healthy enough.
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ACCOMMODATION - Like Dan said looking for second year accommodation early is essential - first few months are really lax on all courses excluding medicine so make sure she spends a lot of time with her flat mates/new found friends. The best houses go really quick and aren't any more expensive than the ones she may be left with if she leaves it until after xmas.
WORK XP - Getting work experience in the summer before second year is so ridiculously beneficial in distinguishing you from the hoards of other average students. To get into good placements they will all be wanting 2:1s on completion of first year - you won't be needing to be locked away to get this result in first year either. The ones who did are the ones who have secured the best jobs immediately after finishing.
INSURANCE -, my halls were very safe/secure but insurance is still a must when going to have laptops, ipads, cameras and whatever else about. Good idea to lock her room every time, albeit pedantic, she leaves even if its just to the common room or w/e. Will stop the 'frapes' and practical jokes if nothing else

JOIN A SOCIETY - this one is massive, even if its something she hasn't done before, doesn't have to be sport. But meeting new people and networking is absolutely essential, get her to force her housemate along to something. The more people you know at uni the better. Becoming a president for a society/your degree course looks good on a CV and is pretty rewarding - again everyone on the course/society will know you/ you have some importance doing your role.
PART TIME JOB - TICKET SELLING, one of the easiest jobs at uni will be ticket selling/advertisement for clubs etc. The easiest money she will ever make and it forces you out, people will get to know who you are. As she's in halls first year be easy to sell 50 tickets for a night out within 500m and a minimum of 50p commission for everyone sold.
ROUTINE - Give herself x amount of hours a week to read over notes/do the work set. Lock your room/be in library for x amount of hours and don't leave until works done/hours finished. No excuses.
Don't care or act on other people mocking you for the society you choose or the amount of work you do, try to filter out peer pressure. Get things done and then go mental when they are. Laugh at those unemployed when you're having weekends away with your graduate job. (I'm the one who didn't do all of these things and now without a graduate job hah)
Pizza cutter!
Whiteboard/pinboard for scheduling/notes - put somewhere that you have to look at constantly.
Diary/blog? Only at uni for so long and I regret not blogging/w/e as I got up to so many different things that there's no chance of remembering them all, or their names (wheyy)
Pictures of family/friends - I wasn't ever one for this but some people can get very homesick.
Email/letters - may be a good idea to write a letter to granny or email mum/dad every week or fortnight. (Granny might enclose a fiver as well if you're lucky lol) Definitely a feel good factor for both parties when they're away from each other.
Set aside a time each week to skype call instead if that's a preference.
This is all a massive ramble as there is so much that could be said/done different/more efficient, but hopefully some of it makes sense.
Agree with what MLHMLH said about enjoying last few weeks with her, she's going to be a completely different person when she comes back having lived in Student halls
