Why would she take a bus for almost $300 when she could fly for less than $50 one way (even with added fees it would still be about $100 and the trip would take hours not days,
https://flights.flyfrontier.com/en/flights-from-denver-to-cleveland
(1) afraid of flying? possible, my brother would drive days to avoid flying
(2) Traveling with things she can't take through TSA (I'm not saying necessarily illegal things, but some people ( such as cosmetologists, artists, engineers, etc.) use components, paints, liquids, and such in their work that can't be put in checked baggage due to flammability.
(3) not eager to get there? Delaying tactic?