Try talking to your manager, tell her what you were told when you took the job. Can you switch to 12 hour shifts? Then you'll be home 3 days instead of 2, or go part time? Is there a possibility of rotating, days and eves?
I prefer nights myself, you would be asleep while they are in school, home in the evenings, then work when they sleep.
2 months is rather short, it may not look good, but your emotional and physical health are important too. Are there other places in the same place to transfer to, with better hours?
There are always more options than just quitting, see if your manager has any other solutions.
Good luck and God bless