If i was you mate i wouldn't drop the charges against her as i think the charges will help you to prove what sort of person she really is. Try to get her to put her request (you drop charges and she lets you see kids) in writing as you may be able to use it against her as it shoots down any claims she has against you that you are an unfit father, how come if you drop the charges all of a sudden she thinks that you are fit to see the kids but if you don't drop them you are a violent gun maniac.
You would be surprised how much of it is stirring by solicitors. When i split up with my wife years ago, she went to see a solicitor and i received a letter from them a few days later saying that they wanted this and that from me including my car. When i showed it to her she was genuinely shocked by it and told me that she hadn't asked for any of it as we were sorting things out between ourselves. Fortunately me and my ex still get on really well and were able to sort it all out very amicably and solicitors never made a penny out of us.
I hope things work out for you mate, make sure you have a good solicitor and as others have already said, fight her all the way if necessary.