Water only when can stick finger in about 3 inches and dry
Using bottled spring water
Happy frog soil
I think you are too afraid of overwatering. Honestly you should be able to water like once a day if your soil is draining well enough (not that you "should" water each day, but it sometimes helps when dialing down deficiencies and things of that sort).
I'd be willing to say that lady isnt getting enough water. I wasnt watering my current run enough and they took forever to veg. I started giving them considerably more water and they all got way healthier.
And there could likely be a PH problem. You can probably find a decently priced PH pen online; hardly a sketchy item to order if thats a concern. A PH pen is probably one of the best investments a grower of any size could make. PH strips/color testers "work," but they might as well work for crap especially when it takes a few PH adjustments on your water to get it to where you want it to be.
Happy frog is good soil for starting and only really great from seed to harvest if you are experienced with nutrients and have them at your disposal. I'd say in the future start your plant in happy frog with about 25% added pearlite, and transplant it into Ocean Forest with about 25%-35% added pearlite and dont wait until the top 3 inches are dry, lift up your pot and judge by weight.
A properly watered plant's soil is going to be a lot heavier than you think...
At some point though your going to need nutes. I'd suggest FF grow big, FF big bloom, and FF tiger bloom; they will work well with the mycorrhizae that comes in Happy Frog. Do not start feeding them quite yet though cuz that NL looks like it may be sensitive to nutes? But those 3 ferts are pretty easy to use especialy if you grab one of the feed schedules.
And did you start that seed in the 3 gallon pot? sorry if thats answered somewhere. When you start a seed in a huge pot the plant spends forever developing its root mass. That being said once the root mass is developed and its watered properly it should explode in growth