Props to you for sticking with it. Finishing your first grow all the way to harvest is the absolute best way to learn, even if a plant gets a little stunned early on. The experience you gain from reading the plant in late flower and dialing in your drying/curing process is worth its weight in gold.
Your environment specs are actually looking really solid:
pH 6.2 is right in the sweet spot for soil.
Temp (24ā28°C / 75ā82°F) and Humidity (54%) are great for mid-flowering.
Here is exactly where your plant is at right now, how to maximize it, and what to realistically expect.
Can You Still Make It Grow More?
At Day 45, if this is an autoflower, its structural frame is mostly locked in. The "vegetative stretch" phase (where the stalks and branches shoot up) has finished, and it has transitioned its energy into building flowers.
While you won't see much more vertical or horizontal plant growth, the buds themselves are about to grow substantially.
From Day 45 to Day 70+, the plant focuses entirely on stacking calyxes and swelling up. So yes, it will still grow a lotājust in weight and density, not height.
What to Focus on From Here to the Finish Line
Because the plant was stunned early on, its root system might be smaller than normal for a 5-gallon pot. Keep these focus points in mind to steer it safely to the end:
Watch the Watering Weight: A smaller, stunned plant won't drink as fast as a massive one. Don't water on a fixed schedule. Lift the 5-gallon pot; only water when it feels noticeably light to avoid choking the roots with stagnant moisture.
Light Distance: A 100W light is great for a single plant, but it needs to be positioned efficiently. Keep it about 12 to 18 inches away from the top canopy during flower so the buds get enough intense light energy to swell.
Watch the Humidity Late in Flower: Your 54% humidity is perfect right now. However, as those buds get thicker and denser over the next 2 to 3 weeks, try to drop the humidity closer to 40% to 45% if you can, and make sure you have plenty of airflow (a small fan moving air around the tent) to prevent any bud rot.
Ease Up on Nitrogen: The plant needs less Nitrogen (N) now and more Phosphorus (P) and Potassium (K) to bulk up the flowers.
Realistic Yield Expectations
When a plant gets stunned early in life, it usually limits its ultimate yield potential because the "frame" of the plant didn't get as large before flowering started.
For a first-time grow with a stunned plant under a 100W light, a realistic expectation is anywhere from 0.5 to 1.5 ounces (approx. 14 to 42 grams) of dry, usable bud.
Don't let that number discourage you at all. A single ounce of clean, homegrown flower that you brought from seed to jar is a massive victory for a first run. Focus on keeping her healthy, watching the trichomes cloudy up at the end, and enjoying the process!