Honestly, I think that overthinking this situation is gonna land you in an unfavorable spot. She's been extremely busy for a while but made time to see you. Your free, go out with her. She made that free time in her busy life to ask you out, I'll roll the dice and say that she wont think less of you by taking her up on this offer. You dont always need to play Mr. DHV, you can do that when your actually WITH this girl. Over thinking everything and playing unnecessary games will drive this girl away.
Thinking about it from her perspective, she likes you, wants to spend time with you and makes an effort to do so. She'll be busy often so she's taking this opportunity while she can to see you but, you respectfully decline her offer and offer another time....she'll take this a few ways...
1. He's also a busy man and cant make the time I suggested. After months and months of going back and forth there's still no together time...what a shame.
2. Im free that day and looking to have some fun. This guy was my first option but, he declined so I'll just call (Random Guy's Name) and I'll have just as much fun. He suggested another time but after all this back and forth...im not sure anymore.
There's a million more I could list but you get the drift. Dont get too hung up on DHVing and go have a good time with her. Being yourself should show enough of a level of DHV that playing these games couldnt even begin to compare to. Im not knocking it or saying always accept her offer, on the contrary, but in this case take that opportunity while she's out there. After a great date between you two she'll be begging for more. THATS when you start getting a life and becoming tougher to get ahold too. From the sound of it, she wants to meet you but she could just as easily say fuck it at this stage and never talk to you again. Take her up on her offer, have a great time, and keep that attraction built. She'll truly be eating out of your hands by then.
There's nothing more painful in this whole game than asking yourself "what if" after something goes sour. Dont make those DHV movements until you're SURE it will be a positive move in your favor. Be an aggressive alpha-male and go take her up on her offer

there's assloads of time to game and DHV but having a grudge on her and trying to "get her back" before this relationship has even taken off the ground will only crash and burn.