There are hints for each girl if you press the heart shaped button.
I have to agree with jajajaja work does not advance the plot for Tabitha or Sophie after it stoped saying the amount you earn and that you can work for more then once a day.
I am around 43 days in with only working as well and only missing those two girls.
::Note:: this was an old save from the previous version. so I only needed the new ones which did not have the hit "work for the day"