Over time, each of your family members will get sick due to overwork and the environment. Try to save up money to treat the whole family at once, it's much more economical this way. Click on any family member, then click Give Medicine to see your options.
Invest in Infrastructure:
While buying a cell phone or investing in a nearby road may seem like an extravagance, over the long term these items will pay off - not to mention boosting your final score!
Go for a long period of time just planting one of each crop. If you don't have enough money to begin with, try selling the children. You only get $10 per child, and only if they have full health, so best to do it closer to the start of the game. Also, if you hav a single adult running the farm, try marrying and them making that spouse leave the farm. You get $20 for the healthy spouse to leave the farm, but the amount you get when they join the family varies. Can only do once per turn and there will not always be a suitable spouse.
How to win:
Press the space bar 50 times in a row to get extra wheat and chickens.
Secondly for medical purposes click on the health button 23 times and you will seek unlimited health.