You've tried hotwire & it hasn't stopped her??
Agree with others, that diet & ulcers are likely candidates for why she's colicking. While cribbing is linked with colic, etc, I don't know that there are any studies to show it causes it, but the cribbing starts as a symptom
of gut probs that also cause colic.
And yes, if you can't control her environment(remove/hotwire rails, etc) then some kind of cribbing collar(different ones better for some horses) or grazing muzzle or such should help you manage the problem. As it's an obsessive compulsive thing & said to release endorphines, it's almost impossible to break the habit in an established cribber even once the cause(gut probs/diet/stress) is removed.