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For someone busy and on the go, I don't normally recommend kava extracts, but the one I recommend is Bula Kava House's CO2 extract. They're selling it discounted right now actually:
https://www.bulakavahouse.com/products/co2-kava-concentrate-honey-orange-vanilla-30-grams (they're throwing out discount code "CONCENTRATE5OFF" as of this writing.) Be advised that most kava extracts are often made using non-noble kava varieties as well as aerial plant parts to keep prices down. Exercise diligence if you find BKH's extract cost-prohibitive and want to look at other extracts.
Another solution which I highly recommend is using instant kava. Much like an extract, you're sacrificing cost-efficiency with convenience, but the nice thing about instant kava is they make it from grog using fresh root (in contrast to dried root) and then they dehydrate the grog so you have a powder you can reconstitute with the desired amount of water and you can simply drink up! In addition to BKH's CO2 extract, I also recommend their instant kava (as of writing, it's sold out.) Gourmet Hawaiian Kava also has great instant kavas but Chris only makes these on occasion and they sell out quickly. Rumor has it he's producing some Nene instant and will put that up for sale soon, so keep an eye out here at the forums so you can buy some in time.
Medium grind kava is your best value, but it requires some preparation, and it's often too time consuming for small quantities (at least without using an Aluball or two.) The traditional preparation for kava involves kneading the root (powder) in water for several minutes (5-10, but 15 is not unheard of) and then filtering out the solid material. A fine mesh strainer bag is essential for this method as some of the solid particles can cause stomach upset if ingested. A more convenient way to have medium grind is to use Kavafied's Aluballs. These are balls with a mesh inside to allow water to saturate the kava root powder contained within. You take an Aluball or two (a larger shaker could accommodate more balls), put root powder inside of each one, then you fill your shaker with water, then shake for about 1 minute (I hear 30 seconds also works, but I doubt many count the seconds), then you pour some into your cup and drink. While using medium grind powder has a bit of an initial cost, once you get into a kava grog habit, you save a lot of money compared to buying extracts or instant kava. The traditional prep method with a mesh strainer bag is typically best when you make large quantities of grog as kava grog is traditionally a social beverage consumed by multiple people. The Aluball is great for 1-2 people. What also makes medium grind very cost effective is that the medium grind powder can be reused. Depending on how much time you have, you can get 2nd washes, 3rd, or beyond. A blender is your friend to macerate used kava grounds further. I myself will use the same grounds to make a 2nd wash with fresh water, then mix the 2nd wash with the 1st to tone down the strength and have more volume of grog. But everyone around here is pretty varied on how they prep their grog. We have many threads here specifically about kava preparation, so give those all a read!
This may be a lot of information to absorb but kava is a complex subject and a message board like the Kava Forums wouldn't be so warranted if it was not possible to get so in-depth. But we're all here to help you start your kava journey, or in your case's, your daughter's. And if kava is ultimately not the solution to your anxiety problems, we won't hold that against you. We're all pretty easy here.
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