What kind of collar is she wearing? (regular collar, type of "training" collar etc.) if she is wearing a choke collar, prong collar or head halter then that could be the cause of some of this, she associated walks with unpleasant feelings so she tries not to go. You might switch to a harness for at least a little while.
A a lot of puppies will do this sort of stuff, leashes and collar are new and threatening to them. Let the pup drag the leash around at home (if you are there to make sure he does not get tangled on anything). When on a walk NEVER try and pull her when she won't move, wait her out, let her throw her tantrums, if she wants to walk backwards then slowly walk towards her while she backs up so there is not tension on the leash and when she's done flipping out encourage her to go forward. Anytime she is walking normally toss her treats, talk to her, bend down and give her some petting (if she likes that) or bring a toy along and let her shake it around or stop for a short game of tug when she has been walking well. Treats might be your best bet though, IF she likes food a lot. Don't bribe the dog to walk with them by holding them out and wiggling them in front of her to start moving, give them WHEN she is already walking well at random times throughout the walk. To kill two birds with one stone make sure you give treats only when she is walking politely (no pulling!) unless she is an "extreme" walker and either holds back or pulls forward and nothing in between but hopefully that is not the case.
All in all just let her take her time, once she realizes that the collar and leash aren't horrible, evil devices and they are just there she'll get over it, so it's important that at this time (and preferably forever) she never sees the leash and collar as bad (so no collar pops (also called leash corrections), no "training collars" or trying to drag the dog along when she does not want to go (she is afraid remember) AT LEAST until she is well over this problem and better yet forever).
Good luck!