Jess will never be poor, nor will Ines. Just in property alone, they are worth MILLIONS. And we only know of 3/4 within their immediate family. I'm 100% sure her mother/step father probably have a larger property portfolio that they have accumulated to diversity their wealth.
I also think she has a trust fund she has access too now and she gets a monthly stipend however its such a monthly stipend that I dont think she would ever actually spend that much money a month. The trust and any inheritance will surely be invested and reinvested too. Jess mother and FATHER (he's rich too, dont forget) have most likely been accumulating hundreds of thousands a year just from their investments.
Once your that level of rich where you have a salary of millions a year as a base and then diversified incomes, it will be very hard for them to go broke just because Jess decides she's not working. Jess may not be sensible but the financial advisors behind her parents and step dad clearly are guiding them in the right direction.
She most likely doesn't have any mortgage on that property and her mum probably doesn't mind living with her first grandchild! So many families are multi-generational, its really NOT that strange. You're all thinking as if she lives within such close quarters of her mother when in reality they all their own bloody floors in that LDN home. I bet they even have help.