Animisha I'm glad you (and many others) find Molly's info useful. I feel differently and think her "generosity" is, like so many other YouTube music tutors, gurus, teachers, experts, ultimately money-driven. There is nothing wrong with earning from teaching. It's the "scientific aspect" of Molly's schpiel I that makes me prickly. Some aspiring music students may embrace her way of practicing, and some might feel a connection to those methods. Good for them, maybe. I'm skeptical of "new" approaches to methods that have worked for so many in the past, especially with something like music. Reminds me of the Atkins Diet
To me, learning to play a musical instrument isn't rocket science, or even neuroscience. The process is simple - you develop technical aspects, study the theory, and work at it. Think of all the outstanding pianists, composers and virtuosos, who have graced the past centuries. How did they ever manage without that right brain, left brain thing? Without someone giving them arbitrary figures on how many times to practice something?
If someone wants to learn to play a musical instrument, they should seek out other players of that instrument, ask them what they did to get where they are, and find a teacher (a live, in person, beside them on the bench teacher) who understands the path the student wants to take, whether it's wanting to play jazz, classical, or just play Christmas songs when the family gathers, and practice, and study, and play. That's it in a nutshell.
However, some students, no matter how much they practice, no matter how they practice, no matter how long they practice, no matter how many books they read, or how many YouTube gurus they subscribe to, will never reach the level to which they aspire. In my thirties, I gave guitar lessons for several years, mainly to young guys who wanted to play in a band and make lots of money. Sadly, for some of those students, it was clear to me, right from the start, that the most money they would make from their guitars would be the day they sold them.
This is probably my last word on "things Molly", having spent too much time on it already. You and the other Molly-ites can call me prickly or edgy, or whatever. I felt like offering my perspective, just in case the Emperor really isn't wearing any clothes.