kitty, I was diagnosed in my 40's when the consultant confirmed from my medical history, I'd had it from the age of 25 at least. I was reluctant to take the drugs but did so. About five years ago it became so bad I was prescribed the biologics that you self inject weekly. I know there are risks with the medication but in my case, it gave me my life back. Prior to starting I had no energy, constant pain and so restricted socially.
A good mattress is essential, as are chairs of a reasonable height. So much modern furniture looks lovely but it's too low to the ground for comfort. Keep active, don't put too much weight on. So far as diet is concerned, the experts all tell me there isn't any evidence to support cutting out certain foods unless, of course, you find they cause a flare. I can't eat Chinese, if I eat too much meat, cheese etc I notice I'm not as fit. So, a good diet with more vegetables than meat, oily fish 3 times a week. Try and avoid stress or find ways of managing it and get enough rest.
Newquay, your daughter is doing good isn't she. I often feel this is one of those invisible illnesses. People tell you how well you look and have no idea about the level of determination it takes. The good thing for your daughter is the medications continue to improve.