Coffee grounds are full of good stuff for your plants. Like magnesium, potassium, and even nitrogen.
However they are acidic. You will need to keep an eye on your outgoing pH levels. Coffee grounds also help prevent Fusarium, Pythium, and Sclerotinia fungi from invading. Even help deter slugs and snails if sprinkled around the plant. That is if your growing outside.
As far as your stems being small, how far are your lights from the plant? Is she stretching to reach them? If she is tall and thin, bury her deeper and put more light on her. I’ve done that before. Lastly, like mentioned above, put a small fan on them. Just get the leaves moving a little bit. That will help as well.