Some of my friends and I do a little "preschool" together with our kids - 2 hours a week 2 days a week, and we switch off who is "teaching". We do fun activities, sing songs, go over some basics, like letters and numbers. We have theme each week that goes with the letter of the week. For instance, A - airplane, B - bugs, C - circus, you get the idea. Then we do activities related to that theme, and sometimes we had "field trips" where we went to various places related to the theme. For instance. When we did A - airplane, we made paper airplanes, read some books about airplanes (from the local library), and I have a CD with some kids songs that had a song about airplanes that we listened to and they got to "fly" around like an airplane. We made some little air foils on a straw and put them on a length of yarn and turned on a fan to see how planes go up in the air. The second day I arranged for us to go up to the local airport (the small municipal one) where an older gentleman met us and told us about airplanes and let them climb around in a few private planes. The medic helicopter was there too, so they got to go and see that as well.
I like doing the basic theme idea because you can adapt it to whatever the kids are capable of doing adn what they are interested in. Last year we worked on just recognizing the letters of the alphabet. This year we'll be working on writing and hopefully learning to sound out words using the letter sounds.
As far as your decision, that has to be up to you, but this could be a fun option for you. It would give you a few hours to your self each week to get something done without her, but still allow you to be a part of her preschool experience. My son loves it and he's been begging all summer to do it again. He'll be 4 at the end of September, so he won't be able to start for 2 more years as well. He knows there's a school for bigger kids, but he's been perfectly happy with what we do.