Your plant looks pretty good man your goind a great job and you have gotten some good advice already but I will chime in if you don’t mind.
First off whenever you have time read the articles on the website, growweedeasy and royalqueenseeds all are very solid websites you will be referring back to many times.
As to your chief concern its hard to point out exactly without some info, I’m leaning towards light nute burn but Im just guessing at this point.
What’s the high/low of your grow space with both humidity and temperature?
What’s the PH of the water you are giving her?
Where does the water come from? What’s its ppm?
If you don’t know already ppm is the measure of solids dissolved in the water, both PH & ppm are important to check going in and the in a run off water sample (keep a grow journal for this reason it will help you alot) so get a PH pen and a TDS meter (spend around 100$ online on a PH pen, you won’t regret it the cheap cheap ones don’t work)
You said your 9 weeks in are you feeding any nutrients? If so give us some info on that.
As for harvest t your little hairs (pistles) are all still white so you have quite a while to go but it will depend on the type of high you want check this chart out
I woild advise against a pocket microscope as they are cheap and hard to use, the best way to use them is to cut a sample so you can hold it steady and no one wants to cut the plant early.
Instead I would opt for a USB microscope that you can click into your phone, these are still not the easiest to use but much much easier and gives you pictures that you can share with us.
I would also get a jewelers loop if the moneys not a huge deal because the loop will be ideal for daily checking (at least I’m told I don’t have one I just use the USB microscope plugged into my phone)
Read up on harvesting is your best bet, you don’t really need anything if you can use your tent, fan, & humidtor/temp sensor.
2 weeks before harvest you flush with cold water, until your soil has no nutrients left so you’ll be using alot of water everytime you flush (Ph’d water)
Then before you harvest cut all the fan leaves off and then wet trim it, hang it in your tent turn off the light and keep the fans on low.
Once a branch “snaps” its jar time, put them in a Mason jar with a humidtor (or a bucket but I found glass works better) check on it at first alot and anytime it goes above 62% Humidity let it air out. After a bit you’ll be doing it less and less it will stablize at 62% and after its stable and your not burping anymore toss a humidity pack in and let it sit checking on it once and a while.
Should take 2 months from the time you first jar it to the time it’s ready and cured to smoke so be patient.
Oh also all drying and curing should be done in darkness so store your jars in a dark place