My pup bitten my OH!

Hey all i have made a similar post about aggression in puppies before...unfortunatly my pup is still showing signs of aggression and it's worrying me.
Yesterday my OH put some orange peel in the bin and Tish made a beeline straight for it and managed to get it, my OH took it off her and Tish bit her. I wasn't in the room but i heard it and it sounded aggressive. I know the bin shouldn't have been in her reach so i have moved it.
Also Tish keeps going under the xmas tree, she has already chewed through a set of tree lights and chewed a branch off the tree so we really need to keep her from the tree. Problem is when she goes under it and we call her out she ignores us. The only way to get her out is by going under and getting her, well she goes for us then too.
I really don't know what to do anymore. Tish is a lovely friendly dog and i love her to pieces but i'm worried about this, that maybe she will bite one of the children. She only shows aggression when we stop her doing something naughty...why is she doing this? Do you think she is a bossy dominant dog? I'm very concerned.

How old is the pup?

Hello...she's 14 weeks. Always forget to add that lol

For starters you could keep a house line on her - then you can get her out from under the tree without crawling after her!

Hope this helps.

I have heard a lot about house lines, think i trip to pets at home is in order to buy one. Are they expensive?

Can you block off her access to under the Christmas tree? I would attach a short length of rope to her collar (perhaps 5 feet) so that if you need to remove her from a situation you don't have to touch her collar, enabling her to bite you. Each and every time she bites or growls then quietly tell her "no" and put her into another room briefly for some time out. She is still very young and just testing the boundaries.

Something like this Long Line (link) would work fine, I'm sure

She is still only a baby and just like human babies pup's need to be taught right from wrong. I doubt if this is aggresion sounds more like ordinary puppy behaviour. I know her little teeth are sharp and they hurt when they make contact.

I would get a crate for her not to be used as a punishment but as a retreat and a place of safety for her. to go to put her blanket and toys in with her . This way your electric cables won't get chewed and the puppy will not be in danger of being electrocuted. It is a shame but some puppies and Chrstmas trees just don't go tpgether.

We had this with our jack russell puppy. She was very aggressive at times and would go for any one of our family members, both skinned and furred. We have gently but firmly taught her what behaviour is acceptable and what isn't. She is now 7 months and 90% of the time is a pleasure. She occasionally goes off the rails and needs a firm reminder, but on the whole she is a normal sweet puppy

if you dont have a crate you could try getting a big cardboard box and cutting a hole in it for her to get in and out, it sounds to me like she quite likes a den sort of thing, hence going under the tree all the time, I would however get a crate very soon for her before she really hurts herself, wire chewing is not good,.
how many kids are in the house? how old are they?
make sure the kids are not grabbing tish by the collar all the time, I see so many neck sensitive dogs due to kids over enthusiastic interaciton with dogs,,,,

IF you do give her a den, make sure the kids never take her out of it or mess around with her through the bars, try not to disturb her at all if she goes in there, that way its a place of saftey for her,
I had a rule when gordon was young, if the dogs in its cage leave it well alone,. if hes out, you can play with him, that way the dog learns when its had enough and wants some peace and quite it can go to its crate and get some.