Young birds will go through a “beaking” stage which is similar to teething. Basically they are learning how to use their beak and the strength of it. If this is the case, it isn’t a deliberate bite and often saying something like “Be gentle” in a firm voice can make them understand. Birds also use their beak to grab a branch or perch before they step up and they don’t understand not to grab a finger too hard. You might try stick training her as some birds transfer to a hand from a perch better than from their cage. It is also possible she is a bit older than you think. Some birds can be timid in a new home and be very gentile, but once they settle in, their bad habits come out. As far as chewing on your things, you can have a toy nearby and offer her that instead of your phone or laptop. Parrots chew and to them anything can be chewed on so the owner needs to provide something appropriate.
Birds do tend to favor one person simply because this is their nature. Even if you do things to prevent hormonal behavior, a bird may still choose a favored person or even gender. The bird will often be fine if handled in another room away from their chosen person.
Since she likes to hide in a fern, it sounds like she might have a bit too much freedom. While a Boston Fern is considered safe for pet birds, letting her hide in it will indeed eventually trigger nesting behavior. If you are allowing her to roam freely, even supervised, this can contribute to her biting. It’s best for one of you to be holding her when she is out, or get a play stand that is separate from her cage and let her be on that when she is out. If she is allowed to come and go from her cage as she pleases, this removes some dependence on you.
As long as you are feeding her a nutritionally balanced diet along with some fresh foods, you don’t need to try to monitor her calories. The caloric intake comes into play when you have a chronically hormonal bird that won’t stop laying eggs. In this case there are a lot of things that have to be tried, including monitoring her calories.
Birds generally do fine with their owner’s schedule, but if the bird becomes hormonal, limiting daylight hours to 8-10 is possibly helpful.
Birds will groom a beard, hair, body hair because if you were a parrot, you would groom each other. If she gets hormonal when she is older, then you might have to stop letting her do this, at least during the warmer months.
Here are some links about training and diet that you should find helpful:
Caring For Your Bird
Bird Food Guide
Thank you for asking Lafeber,