It's scary, but it's not hopeless.
I am sorry for you and Vera, though. It's not a death sentence, but it is life changing.
As her mom, you'll want to spend some time getting educated. This site is great. So is the Crohn's & Collitis foundation -- our local chapter puts on presentations often that are very helpful.
Let me take a shot at a few questions. I'm not a medical professional, but my wife has been dealing with Crohn's for a few years.
-- how did it happen? Of course, I don't know you're situation, but Crohns is really hard to diagnose. There's a whole area on this forum for people who can't even get a diagnosis. In fact, a biopsy will not actually diagnose Crohn's. There's not an actual simple test for it like there is with cancer or something. It's a combination of things that docs have to see and even then, new info can pop up that calls it into question.
-- will it get better?: depends what you mean by "better"? the disease doesn't heal, but it goes in and out of remission. Some people go years without symptoms. Others dont. Unfortunately, there's no simple answer. That said, lots of people live (mostly) normal lives with it, so there's hope.
-- do meds work?: Generally yes. But finding the right medical mix is more of an art than a science. What works for one may not work for someone else. And what works today, may not work in the future. But there are lots of good meds, so the docs can switch off and find things that keep it under control for most people.
--is there remission?: YES!
-- costs do insurances cover?: yes, generally. Many of the drugs used for Crohns are the same one used for other things -- like arthritis. That helps too. It depends on the insurance, but they've been good to us. In addition many of the drug companies will help with the cost of the meds if you ask. My wife is on Cimzia and the company that makes it picks up most of the cost, even though we are not in a financial hardship situation or anything.
It's complicated and you'll be overwhelmed by information. It's a complex disease and has lots of different ways it shows itself. Don't loose heart. Lots of people deal with it. You're not alone.
Keep us posted.
--kevin