I think you're mixing up a few things.
Teaching students a second language is a very different process from how children learn their native language. Very young children aren't normally formally taught their first language - they acquire in mostly by mimicking and repetition. They learn the grammar through trial and error, and adult correction, but not formal instruction. This is true for any language, not just English.
Later on, as they reach schooling age (around 5 years, although that of course varies widely by country and family), they may then start to get some formalized education in the nuances of their native language, but basic vocabulary is picked up far earlier, normally around 9-18 months.
You can find a plethora of information by looking on the internet for "first language acquisition", but here are a couple of basic links to get you started.
Child language acquisition.
First language acquisition
It seems like your friend is talking about 2nd language instruction for children, which has again a whole lot of different methodologies and pedagogies. Your friend's approach sounds similar to various chanting approaches, as well as the age old process of repetition.
I recently attended a brief workshop on vocabulary instruction, based on the methodologies of Jim MaDiarmond, and his Development Language Process, which focus on installing language into long-term memory.
I highly recommend checking out the
his site and purchasing his book called
Replacing Thingamajig. It has many elements of another approach referred to as "total physical response", which utilizes physical movement as part of the memory process.
Here are a few videos to give you an idea.
Video #1
Video #2
video #3
Here's another video, which starts with the basic vocabulary, and works up to the entire sentence. If you look carefully, you'll see the flash cards actually include the article, but when articulating, she doesn't include the article, but introduces it later. She's also using elements of physicality in her instruction.
Video one- vocab intro
Video two - the sentence - You'll note she introduces the articles here.
Video three - the question form