Lemon Wonder Auto very first grow

This is what you call Phenotypes. Think of it as two brothers. Both same parents, just difference looks and traits. I have two polar express plants going right now. They are conpleatly different than each other. One is showing dominant Sativa and the other is defiantly a more hybrid.

It looks like you are nearing the flowering point of this plants life. You can expect the plant to start growing like crazy and double if not more in size. This will happen in the next 2-3 weeks. Also, this really comes down to the plant genetics as well. An Indica dominate plant does not stretch nearly as much as a Sativa. Some Sativa Autoflower strains will nearly 4x their height in flower. The growth will slow after week 3 usually and the energy is then driven to bud formation. But they do still grow more just not as much as the first few weeks of flower. I suggest you do a quick search on the strain here and see how much growth happened with others during flower. I hope this helps.

Your plants are in veg and high RH is ok for them. its not ideal but it won't harm them. The thing you want to avoid is higher RH in flower like 70%+ as it can help molds grow and they then rot the the buds on the plant. Keeping them out of direct rain fall also helps so the buds are not wet + high RH. High RH can also cause something called WPM, and its a bitch, its a fungus that grows on the cannabis leaves. Its hard to kill and some products your spray on the leaves help a bit, like 30% but the fact your getting the plant wet is a bigger issue and I avoid them. I would not use cat litter in them, that stuff is clay or salt crystals with a bunch of other crap in it, and as soon as its saturated it will become useless and cause issues in the medium if you sprinkle it into the pots high EC burning or turning it into mud. There is no easy way to lower the RH other then using a dehumidifier, but given your outdoors this will have no effect, its mostly for indoor grows. If you always have high RH growing sativia like stains that are more airy buds is good as it allows proper airflow to help reduce wet spots and mold. Good Luck!