**Disclaimer** This is not meant to offend anyone who doesn't homeschool their children. This isn't meant to offend any teachers on DS who work very hard to educate the children of this country. This is my opinion based on my family and our situation. This isn't meant to insinuate that if you don't share my views that you are wrong and I am right. This is simply just how my husband and I choose to educate our children.
I am a SAHM to a 6, 4 and 2 yr old. I've been homeschooling for two years now. It takes some creativity and planning to homeschool with little ones at home, but it's definitely doable. As another posted stated it would be no different than in a traditional classroom as the teacher is dividing her time and attention between multiple children, many more than your wife would be.
When we do school, my youngest sits at the table and colors, plays with legos or small manipulatives. If he's not into sitting still or is too noisy, he goes out in the living room to play with special "school" toys that he only plays with while I'm doing school with the other kids. Since they are special toys that he normally doesn't see they hold his attention longer. Sometimes we'll do some school as the youngest is just starting or finishing his nap. I've also included him, especially if we're doing something kinestetic or hands on, he loves it! My youngest has a much better vocabulary, is more interested in school and loves to participate with the other kids. I honestly think it's because he's modeled a fun, hands on environment in which to play and learn. He asks me to do school right along with the other two sometimes:)
The absolute beauty of homeschooling is that it's not cookie cutter. It's not one size fits all. You custom tailor the activities, environment, schedule to your families needs. It teaches your children flexibility, creativity and how to go with the flow. I love it, I am blessed to be able to stay home with my kids and teach them. I think it's awesome that your wife wants to give up so much in order to teach your daughter. It's a huge sacrifice on her part.
One thing to also keep in mind is that you can use so many "non-traditional" opportunites as teachable moments for your daughter. Your wife can teach her when they are at the park, at the store, at the post office, at the doctors office, at the library, the list goes on and on. Would a traditional classroom take a bunch of Kindergarteners to the store to teach them about volume, capacity, weight and measures? Your wife can. She can make the lesson "come alive" for your daughter and use real life experiences to cement in the objectives she is trying to teach.
I am not going to lie, I'm obviously biased. I am pro-homeschool, no doubt about it. I went to public school for K and 1st, hated it. Went to perochial school 2nd through 8th grade, liked it. Went to public high school, hated it. I had no intention of homeschooling my children. But once my oldest son was approaching school age, I was concerned about putting him in school and what type of education he would recieve. I was concerned if the teachers would be willing to invest the time, energy, patience, and if they could. Could I expect them to do that for him, when they have other children they are responsible for teaching? What would happen if they didn't?
My Mom homeschooled 4 out of 6 of us (myself and one other sister went to traditional school) and the four that are homeschooled are flourishing. One has a Masters, two are in college and doing great (both made the dean's list as a matter of fact!) and the youngest is in high school. Three of them are "special needs" one of which has high functioning autism. Was their education similar to other kids? No. My Mom taught one of my brothers how to write his name in pudding because he lacked the hand strength to write his name with a pencil. Now he's writting college essays.
Think of what you and your wife want your overall goals for your children to be. What do you want their education to give them? What is essential that they learn? How do you want them to learn it? What is important to your family? Can those goals be obtained by a "traditional" classroom? Really ponder that before making a decision.
If all else fails, think about homeschooling on a trial basis. Commit to one year, re-evaluate at the end of the year. Give it time, see what happens. Give your wife a chance to see what she's able to accomplish. Give your daughter a chance to learn something. Give your little one a chance to learn how to keep themselves entertained or join in the fun! GIve yourself credit for being open-minded and flexible enough to even give the homeschooling thing a shot!