I am a SAHM to 5 ages 9.15,18.20 and 22. I have been a SAHM since the 22yo was 3.
I started homeschooling when my oldest entered 1st grade and continued through 2005. When the youngest was about your daughters age I discovered http://letteroftheweek.com/ a wonderful curriculum free online. I used this for preschool through K and we loved it. Check it out, it's something you can do perhaps while the youngest one is napping or playing nearby.
Kids even her age, do well with routines. Make her a chart...we get up at 7:00, eat breakfast, play with mega blocks/etc, read, whatever you want on the chart. Kids get in less mischief when they don't have lots of free time on their hands. I'm not saying to run her in the ground, just direct her more through the day. She does need lots of free/creative time because she is young. But this curriculum doesn't take a lot of time each day & it has been my personal experience, that when the board comes out, they are ready to go.
Enjoy being a SAHM, it is the best, hardest, most challenging thing I've ever done and I would not trade one day for all the money in the world.