On the working hard point:
High paying jobs require many years of very hard work. It would be exceptional to be paid a lot without having worked very hard for it.
Some lower paying jobs require sustained hard work too, but not all.
So hard work is an ingredient for high pay, but not the one and only ingredient, you need to combine it with other ingredients:
Some lawyers (see criminal barristers, basically public sector work) are on less than minimum wage. Some lawyers earn 7 figures. They all work hard. They are all lawyers.
Musicians, actors, dancers work extremely hard. Only a few earn well.
Private sector is easier than public sector.
Jobs requiring thinking, intellectual skills, analysis, entrepreneurial usually get more pay than manual jobs.
Typical "female" jobs: caring, cleaning, teaching children, cooking, sewing, PAs are less well paid than plumbing, bin collecting, groundsmen.
If you can find something you like in the private sector, non manual, not "typically female" AND work hard, chances if a high salary are very good.