Hi all,
Just a tip for those who are struggling with the first level 50 jump on girl #11. (which I did a lot around company levels 11-14)
Everyone says girl #3 and #11, and indeed that is true, girl #3 can help a lot with the big jumps on #11.

A great help for the first jump (the first level 50 jump for girl #11) is to level up girl #6. For some reason (coding error or intended) that girl gets her 50 level jump 25 levels later than the others. So for a way lower cost than any other option, you can push into a higher income bracket.

The reason is similar for why girl #3 is so good.
And at higher level, after 'The Big Black' on girl #11, girl #2 has a very good option too.

After I unlocked 2 girl specific decorations, the game sped up incredibly. So they definitely worth scouting for. For me the seats I sit my top earners are: #11, #3, #2, #10 in this order.