Your friend will sure need to be flexible and must be prepared to a lot of roster changes. Being change from late to early the day before is unfortunatelly very common.
Most crew are nice and friendly. Money is not that bad but as it has been said you do work for it. Night stops are now numbered. The further away she will be night stopping will be Aberdeen.
The good night stops are definitely AMS and BRU.
The big problem at BMI is management, useless and not always fair.
Concessions are not good. Promotion is easy and fast (for number one) but still very difficult for long haul.
BMI is great as a stepping stone but hardly as a career.