Money Diary: A GP On 57k Who’s Part Of The FIRE Movement

Welcome to Money Diaries, where we're tackling what might be the last taboo facing modern working women: money. We're asking a cross-section of women how they spend their hard-earned money during a seven-day period – and we're tracking every last penny.
This week: "I’m from the Caribbean and moved to England by myself when I was 18. I am in my third and final year of general practice training. 
When I started working in 2015 I became more mindful of my finances. Searching the internet, I found blogs (such as Mr Money Mustache) which opened my eyes to a movement I had never heard of before but which I now follow, called Financial Independence, Retire Early (FIRE). I immersed myself in the movement through Facebook and meet-up groups. Please don’t get me wrong, I have no intention of ending my career in my mid 30s. I do have every intention of reaching age 34 and being in a position that if I did happen to stop working, I could do so comfortably and not have to worry too much about money for the rest of my life. 
Another reason I am doing this is because my severely autistic brother will likely depend on me to take care of him in the future. We have struggled to access appropriate services for him so financial provision for him is always on my mind. 
One of the tenets of FIRE is that to reach the ultimate goal typically involves saving and investing 25 times your annual spending without withdrawing more than 4% per year upon retiring from work. This is all providing that your assets produce an average return of at least 7%. Therefore, my plan is to avoid lifestyle inflation, triple my income and keep my spending at no more than £1,500 per month over the next few years while saving and investing the rest. Currently, my savings rate is around 50% but I plan on increasing it to 80-90% throughout the rest of my 20s and 30s. I realise how lucky I already am to be in this position and I am very grateful for it." 
Industry: Healthcare
Age: 28
Location: Warwickshire
Salary: £56,914.35
Paycheque amount: £3,210 (after tax and pension)
Number of housemates: 5
Monthly Expenses
Rent: £450 including all bills and council tax.
Loan payments: £0. I got a student loan from my home country in 2010 in order to afford my living expenses while at university. I borrowed roughly £30,000 and paid it off by late 2018. 
Credit cards: I took out two credit cards at 0% interest for 26 and 27 months. I used both of them only once to pay the last £7,000 of my student loan. I fully intend on paying them off before their 0% interest periods end. The total balance left is £3,935.34. The minimum payments for both add up to £94.44 per month.  
Utilities: £0 (included in rent).
Transportation: Approximately £80-100 per month on petrol. I pay my insurance and tax yearly (adds up to around £1,200) and I bought my car in cash in 2016 for £3,000. 
Phone bill: £8 
Savings? I have three months' worth of my monthly spending as my emergency fund (so £4,500). I also have a Chip account which removes money out of my main current account every four days or so. It sends me a text notifying me how much it wants to take that day and I can opt out each time if I want.  
Other: Spotify £10. Gym £41. Netflix £8.99. Air ambulance service contribution £4.34. General Medical Council membership fee £156 this year and increases with seniority. Royal College of General Practitioners membership fee £402 this year.
Stocks and shares ISA: Every month on payday, I transfer £1,000-1,500 into my stocks and shares ISA. This goes into various Vanguard index funds and ETFs which track the top 6,000 or so companies globally. My plan is to never touch the money I am investing but to instead let compound interest work its magic so that I can collect the dividends years and decades from now. 
Pension: 12.5% of my pay goes into pension. This ends up being £500.78 per month.