I’m so sorry to read this. Crohn’s is a wretched disease for an adult to handle let alone a kid.
A few thoughts for what it’s worth.
First have you had her iron and b12 checked - both notorious for being low with Crohn’s and not contribute to anaemia which can make you feel weak and tired. If she is anaemic you can get iron supplements, liquid are easier on the tummy than pills, and take with vitamin c to help absorb it.
Second is it worth looking at anything that can be done to support the medical treatment I.e. some folk respond to particular anti-inflammatory diets, vitamin d can help especially if you live north, is she suffering depression (would be understandable) and might talking to a health or clinical psychologist help.
Thirdly their are a few other treatment options and there are new things currently being researched. Covid has caused delays but there are trials ongoing for new approaches. So even though things might feel awful and hopeless, there is more being understood and researched all the time and we are all waiting for one of the new ideas to work. So for example there is a vaccine being trialled in the UK. There are new drugs being tested out. So hold onto that even if humira doesn’t put her in remission, something else might and it might get her feeling better as well and there will further options added hopefully over the next few years.
My advice would be look at what she can do not what she can’t (this is easier said than done). If you are on holiday at the beach she might not have energy for sports but what about a manicure or sandcastle building, that kind of thing. You have to work a bit with what you’ve got because otherwise the focus on what you’ve lost/ are missing out on is just miserable.
Wishing you both all the best and will pray for your little girl.