Freddie. Jess organises their life and Freddie pays for it. I remember when she was buying a tonne of stuff for the garden and put it all on Freddie's card. You can also see from her IG stories today that the booking is made in Freddie's name i.e. he paid for it, but she organised it. She has mentioned in the past that he's very good with money and saves a lot. I wouldn't underestimate her earnings either, though - influencers get paid silly money. That said, I think his job must be very well paid.
Jess also got most of her house furnished for free: I guess it's easy to splash out on fancy food and even fancier holidays when you don't have to pay for much else in life.
I recently started following Jess's sister, Alice, who I think works full time in addition to the influencer stuff. She seems nice and it doesn't appear that her whole life is #gifted (I haven't been following her very long, though). She recently posted the products she used in a facial which included lots of minis and sample sizes - unlike Jess who is gifted Elemis everything!