Bet you guys didn't expect to see a chapter update alert from this story again did you? Well, I just wanted to let all you guys now that I'm going to rewrite the story. "Phantom, why would I care? I already read this one!" you say. Well, not only will the rewrite be different, it will possibly be longer. I'll still hit some of the same plot points, but I'll put a different twist on most of them. If you liked this one, then you'll love the rewrite. My skills as an author have become even better, and I asked for feedback from one of the best fanfiction author's on this site, JBGilroy. I'm trying to make the story even better and more enjoyable. Knowing that this story isn't as good as it could be makes me want to rewrite it. Plus, I had a ton of fun writing it! I'll provide more insight on Jenny as well. Also, I have a poll up on my bio about Jenny, so please go check that out! I'll leave JBGilroy's advice here if you want to read it.

JBGilroy: Okay, I've read that story and the one-shots you wrote.

First, it is an interesting idea and you obviously know your pokémon. However, unfortunately, it needs a lot of work.

First off. A few general pointers to help you throughout your writing.
Beware the !. This simply means know what it means and be careful not to overuse it. I did notice in your dialogue you use ! to make a point. ! is a raised voice, not emphasis. Personally I use italics. I've seen other writers use bold or underline. Just be careful.
Another thing I noticed is you overuse character names. Danny did this. Danny did that. Danny, Danny, Danny. Yes, you need to know who is doing the actions, who is where, who said what. But you can do this without resorting to the character's name. For Jenny, you can use the pokémon instead of Jenny. For Danny, halfa. Depending on who else is in the area, teenager, boy, hero, ghost... and so on. Just be aware of it. I tend to pick three or four things and stick to those throughout the story.

Next. Fight scenes. These are hard so don't feel discouraged by this. I myself took a lot of time to get these right.
In pokémon, fights are fought play by play. It's the way it works and I understand that you have experience in those types of fights. In Danny's world though they aren't fights with rules and regulations. They are thug fights. So don't be afraid to throw in some details. Put in some dialogue. If you watch a Danny Phantom programme, there's usually banter in between the punches.
Also make certain that cause and effect are clear. In your story when Jenny and Vlad first meet. Jenny uses grass knot and it trips Vlad over. It wasn't clear. I had to re-read the sentence a couple of times to understand that's what happened. Rather than saying Vlad flipped over, it would have been better to say his foot tangled in the weeds and caused him to fall flat on his face. But overall, this wasn't the case. I just wanted to point it out to help you refine choreography in fights. A good way to choreograph is to act it out, or draw it out. It just helps you place everything and everyone somewhere outside your head to keep track.

A side point: Vlad was way too knowledgeable about pokémon to start with. He reads a couple of facts and he understands everything. You could have had fun with this and put a inner dialogue for Vlad where he gets very confused. For an outsider, pokémon is complicated and takes a lot of time to understand and pick up. Especially without playing the game or watching the programme at all. Mightn't be a big deal for you and it was corrected quickly, but it did jump out at me.

And finally, what you actually asked for. Jenny. Interesting name and unique description. Unfortunately your quest not to make a Mary sue wasn't successful. A Mary Sue is perfect and while you say in the A/N that she has limitations to her powers, the reader needs to see them. For example, you don't have to take this but you can if you'd like, for me she can change into any pokémon at any time and use any move. It would be better, at least for me, if she was restricted to maybe four moves per morph and six pokémon per time. The injuries transfer to her and maybe the keystone takes time to replenish. Like six pokémon per 24 hours. Big limitations work better than excepts to the rule.

Her origin story. The story of her grandmother giving her the keystone is cliché, at least you didn't say on her grandmother's deathbed. Pokémon hasn't been around for very long, so personally this backstory doesn't make sense. Why not play on the portals to other times and places in Danny Phantom's world? Say her grandmother came to this world by accident, bringing with her two keystones. And when she saw Jenny's interest in the pokémon game series, decided to tell her about her heritage and trained her.
Ace. This dog seems to be a big deal to Jenny. Vlad injuring the dog was enough to send Jenny into a rage-induced frenzy. However I didn't realise it from the story alone. A few details thrown in would have shown this bond. Where did she get the dog? It could be a heart-warming tale where Jenny saved Ace because he looked so much like a wolf.

Also, stop comparing your story to the pokémon series. I know what your trying to do but the little A/Ns throughout commenting on these things are both distracting and unnecessary. Your constant comparisons appeal to die-hard fans but alienate intrigued fanfic readers. This is your story. If people don't see those similarities then it doesn't affect the story, if they do they can comment on it.

I hope that helped and I understand the nerves when trying something new and putting it out there to the public eye. But you did write a unique story and with these small fixes, it would be a really good story.

Good luck in the future and let me know if you need any more help.

I was extremely happy to hear that I had done a relatively good job on my first time around, but this time, I want to do an even better job. I hope you guys will look forward to it!