In one sense, I am no more qualified to teach Latin to my children and to two other families' children than any of the other parents in our circle.
You might think my husband is the most qualified: he took three years of Latin in high school, which is three years more than any of the others. But since he remembers very little (odd bits surface from time to time, like the first two lines of the Lord's Prayer or witticisms like semper ubi sub ubi), 'twere foolhardy to put him in charge.
Or you might think Hannah is the most qualified, since (I think) she's the only one of us who studied two different foreign languages.
But in the end, it was me, and it was Latin.
Why am I teaching Latin, and not French, in which I'm fairly fluent? Because I already know French and I want to learn Latin. When my kids learn a modern language, I hope it's Spanish (for utility in our neighborhood, city, and country) or Arabic (for cross-cultural and international utility), not the comparatively useless French, even though I love French and even though I owe my high school French teacher a major shout-out for teaching me how to learn a language down to the bones. AND the nice thing about the classical languages is that curricula are available which assume the teacher has no prior knowledge of the subject. Self-teaching curricula, you might say. (Greek, Hebrew I think, and American Sign Language are others.)
A better question is why my friends are allowing me to teach Latin to their children. Weeeeeelll, maybe they will pop in and comment in their own words, but I think it has a lot to do with the facts that (a) I was willing and (b) that's one less subject that they have to teach and (c) it's an elective at this stage anyway so even if I screwed it up completely, no matter. I'm flattered that they trusted my abilities to do it.
So I already had been teaching my then-8-y-o for a while from Memoria Press's Prima Latina and Latina Christiana I before the other kids joined, so he spent something like ten weeks on a side project of learning the Pater Noster and Ave Maria while Melissa's then-10yo daughter and Hannah's then-9yo son caught up to him in Latina Christiana. That slight gap has been a little bit of a distraction since my son is eager to show off what he knows; eventually the other two got to the point where they were nearly as comfortable with the material as he, and then we could get down to business. I started working with them regularly twice a week in a "group lesson." The other two would do drill on some of the other days of the week at the discretion of their mothers.
After the other two children caught up and I started teaching all three together, it became clear that we'd have to change the order in which we worked on the material. The three-kid combination I was teaching needed to absorb the material in bigger, more uniform chunks: so instead of learning, for example, a couple of first-declension nouns and a couple of second-declension nouns and a handful of verbs, and one grammar concept in one lesson, we would spend time on a group of first-declension nouns drawn from several lessons until they were all learned, and then some time on the second-declension nouns, and then the verbs, and so on. After the vocabulary was mastered, I'd start introducing grammatical concepts and use the vocabulary to make sentences that illustrated them. We slowed down considerably and I took the children completely off "Scheduled lessons," choosing instead to work on a set of vocabulary or a grammatical concept until mastery. (Readers who use Latina Christiana will understand if I say that we worked on things at the level of the "Review Lesson" -- I would teach all the material in one review lesson at a time, in the order that made the most sense to me.)
As we went on I started inventing my own drill games on the fly. We played charades a lot, and use the flash cards heavily. I also discovered that the kids LOVE translating, probably more than any other activity. This meant I had to come up with sentences using the vocabulary they have learned from their book. What a fun challenge that has been. I give them worksheets with five or six sentences to translate from English to Latin, and five or six to go the other way. Sometimes I write silly sentences, sometimes serious ones. Sometimes I try to ask questions and give them a chance to compose sentences of their own. It takes a little time but it's one of my favorite school-prep tasks to do.
Early on I stopped teaching the "Famous Men of Rome" history material (though I bought the books for our library) and I also haven't used the material on English words derived from Latin. I can't figure out a natural, timesaving way to include material with such advanced vocabulary. We have limited time and we are doing different history stuff (although I think it could probably work really well, and save time, to use this curriculum for classical history too.) I'm going to use a different word-roots program this year instead as a supplement.
Teaching Latin has freed me from feeling enslaved by the recommended teaching schedule of a curriculum. This is the first time I have really taken a well-designed, purchased curriculum and completely changed it around to suit the needs of the children I was teaching. I have bought Memoria Press's First Form Latin, and when we finish the material in Latina Christiana I we're going to switch over to that. I think its approach, which is more rigorous-grammar based, will suit us all better. But in between, I'm going to help the kids build their own Latin binder in which they keep lists and tables and grammar rules, which they can use for reference and continue building on as long as they continue studying Latin.