The reason the budz are so small is likely due to the CFLS but alos because she is a sativa. 3-4 more weeks will give you a decent yield. IMHO nothing wrong with MG. Is it the best option, no but if it is all you have then no problem. As long as you understand how and when to water to avoid burn. And you obviously do because she is very healthy looking. Someone had suggested FF Ocean Forest, I tend to think that soil is too hot for seedlings and clones and can be kinda difficult to gauge when to add nutes for a newbie. I would suggest the FF Happy Frog as a good alternative. Adding some flowering nutes at this point should be ok. Get something that has a higher P and K ratio then N. And as also previously mentioned start small and build. Too little is ok, too much can be devestating. Best of luck to you! and +rep for a successful 1st grow.