I am sorry about your aggressive lovebird. I actually haven't had as much luck taming lovebirds as most all other birds. Even though they are smaller so don't inflict as damaging a bite (even though it still hurts) I would much rather work with a macaw LOL! The female lovebird will usually tend toward more aggression than the male. Especially if she is in season or getting ready to lay eggs. They become much more territorial both about their cage and about themselves. Especially with a male present even if in a different cage the aggression will be more pronounced. Try moving the male to a different cage or different room to see if this helps calm her after a few days. Sometimes the female will become protective of a potential mate and become aggressive if she sees anyone messing around the "mate" whether it is human or another bird. One of our female lovebirds sees our DYH as a potential mate and will scream and go nuts anytime anyone handles him but when he is left alone she calms down.

Try patience, possibly distraction or a treat. Millet sometimes works well as both distraction and treat. Hold the millet in one hand, try letting her climb onto your hand while holding the millet between her beak and your finger "hopefully" she will become interested in the millet and start eating it.

Good luck don't give up and be patient. Even though they are harder to tame and train it is possible. Maybe try leaving her alone for a few days in case it is seasonal and they start over again. You both may need the break.