Go with your gut this is not appropriate behaviour- she's testing the waters seeing what she can get away with and how far she can push.
Honeymoon is over, she's settling in and seeing what the rules are going to be.
Yes to a degree on normal puppy behaviour, although it is not acceptable puppy behaviour. ALL puppies will test to see what they can get away with. 7 weeks, the age you brought her home is supposed to be an imprinting and bonding stage. Many old schoolers and some in specific breeds (sporting breeds for example) believe that is a prime time to send puppies home. However, for a home that is just wanting a loving pet, the extra 2 weeks or more spent with the dam and littermates can make a world of difference in the manners learned. She's crossing a line and no it will not necessarily go away.
I can sense the concern and displeasure her behaviour is bringing out, I'm not sure if I'm also sensing a little bit of fear of her already too.
IF so, then she's already top dog, you need to reverse the roles.
A well founded and perceptive fear, because that is exactly what she can grow into.
She's doing it to test the waters, see where the limits and boundaries are and to display displeasure about things she might not necessarily want to do. This growling is different than what what Nikki is describing Midnight is doing. I have the grrrrrer's when they're getting their backs or tummies scratched and I hit "the spot." I have the ones that "comment" on different things.
Okay, what to do? First - you, mom and dad are all bigger than puppy , you are all going to have to take charge and set the rules and yank a
FIGURATIVE knot in her little bunny butt. (NOT LITERALLY!!!!) Carol Lea Benjamin has a book called
How to Raise a Puppy You Can Live With which is very good. I don't know if you recall some of the threads where Nothing In Life Is Free (NILF) has been mentioned, but I suggest going back in the archives here and checking it out or put it in a search engine and read some articles about that. She's very much still a baby - so make her be a baby. I don't recommend the alpha rolls, as many times those can get you bit. What I do recommend is holding her on her back in your arms like you would cradling a baby. Tickle her tummy, scritch her head and make it a snuggle fun experience - on your part. I suspect she'll react with wiggling, not like it and may try her growling thing - don't give in, or let her go until she's still and calm. She doesn't have act like she's enjoying it when she finally gets calm, she just has to be still and calm. Then you let her go. IF you are concerned about her snapping and maybe getting bit, wear gloves - the heavier gardening type gloves offer some insulation. When you pick her up - arm/hand under her and her feet dangling - play with her feet. Lift up her lips and look at her teeth - she needs to be handled and if she were with many Breeders at her age, this is the type of things they do with their puppies beginning early on. Make games of it - use a silly, happy voice - for example if looking at her teeth, tell her you want to check her tonsils. She learns to tolerate handling (a plus when visiting the vet) and learns to trust she can be handled and nothing bad is going to happen to her.
Voice tone and inflection can send lots of messages and be used for many corrections. When she starts the growling about having her leash attached to her collar - give her an EXCUSE ME??? - I DON'T THINK SO LITTLE GIRL!!! And promptly attach the leash with AUTHORITY in your action while the tone of voice has her startled a bit. Annnnt or Attttttttt are also good corrective noises (words) and can work for some instances. IF you need something more physical in the way of correction, carry a water gun. She begins her growling, shoot her with the water gun, water will startle her and again, with AUTHORITY do what you need to do to her. (Now, if she happens to be one that likes to play with water, this isn't too helpful, turns into a game of a different sort.)
I commend you for noticing and admitting this isn't "cute," for being proactive and wanting to get a handle on this NOW! Good luck and we'll try to help as much as we can.
Debbie