new puppy

 Hi, a puppy what fun!

You need to let the "other" dog (you didn't use names, so I'm not sure how to refer to her!)  know she is not being replaced.  Always talk to her first; feed her first; pet her first; allow her to pass through a doorway first.  lLet her know the puppy is below her in YOUR order of priority.   Give her treats first, do a bit of training with her first.

 You didn't mention how old the puppy is.  If it is young and small, you will need to be present anytime they are together, to ensure the baby isn't hurt.  Once the puppy grows a bit, it should learn to fend for itself, stand up for itself, play with her or leave her be, depending on the body language presented.  Puppy needs time to learn all that, though.

 Its only been 2 weeks. Give it time.

Welcome to the forum... we love puppies too!  Not much to say, I havent had a puppy with other dogs in the home in a long time.

It will take time.

The reality is - you have a new pup, and a LOT of what your new pup is doing, or will do, WILL take priority over everything else.  That's the reality of having a pup. They need to go out more often, they need more feedback (constant feedback when they are loose in the house), they need a ton of training.  Don't worry yourself about making the pup seem "lowest in the pack" - it's not going to mean much else to the dogs anyway. Treat all of your dogs equally, with the same respect and the same house rules.  Keep things as normal as you can.

Make sure to spend some one-on-one time with the other dogs - away from the puppy. Take them for walks without puppy, take them for drives without puppy, when puppy is sleeping play some fun games or teach them a new trick. Don't overdo it, just make sure you make time for everyone.

Make sure you give the older dogs LOTS of breaks FROM the puppy, and vice versa.  That may be your most important thing to do. Some adult dogs do not like how annoying puppies can be - it wouldn't surprise me if your older dogs get tired of the pup's antics from time to time. They need breaks, every day.  Use tethers, baby gates, and crates for that purpose.

If your dog doesn't have any other outstanding problems with new or strange dogs, just allowing them to share the space without them having to be bombarding each other all the time is likely going to be all you need to do to let them get used to each other. As your pup gains some skills, like Sit or Down, you can start doing some group training and rewarding ALL of them for good behaviour. There's nothing like being rewarded together for being calm together.

Other than that, just have patience, and have fun.