You and your daughter need to read these posts alot. Then use the search button and search the forums for any topics you want more info on. The website has just about every marine job, avenue, vessel, fleet, specialty, position, rank, and incident that goes on out here.
Some of the info may be disconcerting, and some may tweak her interest. But, this is a good way to get the unvarnished truth about this career.
In your post #5 you asked 5 different questions. They can’t be answered with absolute certainty since there are SO many variables. Like, what type of vessel would she work on? Oil field supply, ship, tug, ferry, cruise ship, research ship, or in shore side supply. etc etc etc. All these different type vessels have their own nuances and different manning schedules, work schedules, and pay levels. On top of that, some are cyclical, meaning as the economy, the oil price, or some other influence affects it, the job may dry up for a year or two, until the economy rights itself.