How do you pay back a family?

My partners family has shown the upmost love to me. Has helped me in so many ways and means so much to me. They have provided me with a home, with family, with love, with kindness, with financial help, with everything.
I don't know where to start with repaying them. I'm already literally repaying them, with actual money. As they helped me get and stay in this country with a couple grand, not just a hundred dollars or so.
But I want to do more. I'm writing them all nice letters expressing my gratitude for christmas. Getting them all thoughtful gifts. And I've said thank you thank tou thank you for everything many times now.
But still, I owe them my life as it is today and I couldn't be more grateful for them.
I live out of home with my partner in a different city. So i cant really go clean their homes or anything as such.
But still, i need help here, what should I do? Whats more ways I can repay them for everything theyve done for me?