Week 7 flower buds seem to not have filled out yet...

Buds should fatten up at the end when you flush and plant is dying off. Hit them with overdrive and flush for a week or so

Grew this strain 1st hand experience my smallest plant I double potted 2 of them and got three oz from the 2 of them the buds swell slow but are very dense and heavy hold out take it till end of week 9 I promise will be worth it this is a very generous strain if done right and was they from clone I take it Yh hold out bro your looking on three oz a plant and more depending on size

I think @athos is right you pick up most of your weight in the last 2 weeks and flowering may not be done in 8 you could have a few weeks left. Try to get a jewelers loop and base your harvest off of the trichomes, not the pistils

7 weeks is too soon for the flowering phase to be finished. As a rule of thumb 8 to 9 weeks is a good idea of how long the flowering will take for indica dominant strains and for sativas it's closer to 10 to 11 weeks, although it can take longer sometimes. My last run, the buds doubled in size in 1 week or less just before the thricomes turned white. Give it time, it's hard to see the action if you check them everyday, I would recommend that you take pictures of your buds every 5 days and compare them. You will see that they are actually growing.

Hi bud size are really a combination of genetics and grower skill , you may need to add certain elements at earlier stages , do you use a boost ? Cannaboost is a good start 👍

I go by the canna grow guide calc because it has descriptions of each phase; that can be handy in situations like this: "Generative Period II -- Development of the volume (breadth) of flowers or fruit" vs "III -- Development of the mass (weight) of flowers or fruit" vs "IV --Flowers or fruit ripening process" Once you get the hang of the four stages of flowering it will become more apparent how long the plants have to finish, even autoflowers. http://www.cannagardening.com/growguide

Buds needs Sulfur to fatten up, not only PK, you should have stop the Cal Mag for a Mag Sulfur in week 4 of Blooming 😉

I wouldn't worry bro she's still got some time to chunk up with the overdrive and stuff

Friend, the pistils are often deceptive at the time of cutting, I happen to be when I had the 30% brown trichomes was still releasing white pistils ahaha, do your best to guide you by the trichomes at the time of the cut at the end there is where the effect plays! Have a good harvest :)

My bubblegum was similar so long as it was throwing white hairs I would keep letting it go. For me it was an additional 3 weeks beyond everything else in my grow