I'm on an eternal catch-up, but wanted to make my first ever post. Its about mortgages.
Jack says the house is worth £800k, and she pays £1.5k a month rent which is "more than a mortgage would be".
Assuming a 10% deposit, mortgage amount of £720k at 2% APR (which you'd be lucky to get these days) over 25 years, you'd be looking at £3k a month, double what she's paying in rent.
The house looks lovely, it seems like shes got a great deal on it.
Also if you want a mortgage don't go on multiple visits to the bank, find a broker who specialises in whatever your issues are (bad credit, self employed etc). A bank employee will only recommend their products but a broker will search the market.
A quick search of Rightmove has shown there are lots of fine-looking two bed flats for around £200K which would have really managable monthly payments and allow her to build some equity and security