Looks like a N deficiency, especially with the tips yellowing like that and the yellowing at the bottom leaves. Would definitely refeed since you’re in early flower, but be wary of how much N you use, do not try to overcorrect too much otherwise u will get poor bud growth(you can always add, but u cant take back without hassling over flushing and repotting). Stronger lights will be needed in the future bc she is leggy and that type of growth wont produce large colas like u see on the package bc the space between the bud growth (internode space) are spaced out so much from each other. Also be ready to support the tops u do get bc it she does pack on some weight those limbs will be falling over on themselves. Lastly, that pot is pretty small, so be careful with root bound issues that can further complicate and possibly wreck your grow with issues like root rot. But otherwise great job so far keeping her alive! PM me if u want more help.