Chinning is a way of marking. They have scent glands under there so they can mark things as theirs. It’s perfectly harmless and kind of adorable when they do it to you. Biting could be hormonal (she’s getting to that age) or it could be her trying to communicate with you. Depends on the circumstances. Could mean she wants to be petted/wants some food/wants to be put down on the ground… It’s up to you to figure out what exactly she wants at that moment. But completely normal behavior.
For future reference, it would probably be best to make a new thread under the diet tab for the veggies question so people will see it, but here is the link to the
diet page. It’s full of good information about what and how much to feed as well as what to limit or avoid all together. The textbook answer is 2 cups per 6 pounds of rabbit. But it’s important to realize that is the minimum, you can easily feed more. My rabbit weighs in at about 3ish pounds and she eats 2-3 cups of veggies a day. The plate is quite literally as big as she is.
Just be sure it’s a bunny safe veggie, introduce it slowly to be sure it agrees with her, and progressively up the amount she gets until you are happy with it. Once she’s full grown it will be easier to find the ideal amount to feed her by monitoring her weight but when she’s still growing she should pretty much be on unlimited everything so don’t really worry too much about over feeding her. She’ll stop eating when she’s not hungry.