I would not start Humira with your current doctor, to be honest. And I am disgusted that she would advertise herself as a Crohn's specialist when she seems to be anything but: I would bring this up with somebody. It sounds like false advertising.
Re Imuran or 6MP. There is a lab test, TPMT, you can take in advance to find out how well you metabolise thiopurine drugs. A minority of people can't metabolise them properly, and so end up with toxic side-effects such as a lowered blood count. Do you know if you had that test? Even if you get a low result, you may still be able to take Imuran or 6MP, but at a lower dose. Also, you can take allopurinol alongside low-dose Imuran/6MP to significantly reduce toxicity. Since allopurinol seems little known about
, here is a study to prove I'm just not talking out of my arse.
www.ncbi.nlm.nih.gov/pubmed/20015102Even if you end up taking Humira, it still would actually be helpful to take Imuran or 6MP alongside it. It reduces the risk of antibodies forming and the biological med stopping working. And Imuran/6MP are decent maintenance meds in their own right, provided you can tolerate them.
Incidentally I was in a similar-ish boat of having useless GIs. When I finally found a decent one, it felt like it was years too late to be honest. But 3 months shouldn't make a massive amount of difference, so I would wait to see a better doctor.