A few weeks ago her level was 20 i don't what range they use they never give me any copies. And yes she always looks pale and is always tired.
The normal range is 40 to 150. At 20 or below it's definitely iron deficiency that should be treated. At least that is what my experience is (I had troubles with iron on and off since 2007, recently with the right supplements my ferritin levels are in the normal upper range at 100-130 again).
Without the blood test, it is of course hard to tell, it also is a question what her hemoglobin level is. But at a ferritin level of 20, symptoms of being tired and looking pale and being a Crohn's patient, that is quite a strong indication that she has anaemia due to malabsorption of iron.
The problem for many Crohn's patients (me included) is that many iron supplement pills are creating stomach and intestine troubles. Therefore it is important to either find the right supplements (I recommend disolvabld iron supplements, even if they don't taste good, but dissolving them in at least 3 times as much water as recommended, otherwise they are too aggressive). Alternatively, to get iron levels up quickly, an iron infusion may be in order (I had a set of them once, 5 over a period of 5 weeks and the first one already got my ferritin level up from 13 to 35 and after 5 it was at 120 and I felt a lot better).
P.S. I would always ask for copies of every single test done for your own files, I think it is important to have your own complete history of what has been done and how things develop.