I agree with ignore her. I get that her attitude is grating to you, but there is nothing that indicates that Charlie doesn't welcome her input. So you'll need to decide if you can deal with being around her. If not, then you need to figure out a schedule of when you can be onsight when she isn't there or in other areas so you can limit your contact with her.
I understand why your DH was saying the foundation is priority. But honestly, wiring can be done while the foundation is being done Honestly, I'd be fixing bad wiring before dealing with foundation if there was a fire hazard. So your DH "quickly shutting her down" seems just as poor of a response as her attitude does. Your description of the interaction made me wonder if she is the eternal optimist and your DH the pessimist.
Podding this completely. I totally get how Tinas can be exhausting and annoying. But it's Charlie's house. If he find Tina's input unwelcome, then he needs to be the one to say something. And honestly, in this particular context, a sister listing all the people who can help out is a rather sweet gesture (I'm sure she'll be in for a shock when all those people provide their bill, but that's also not something you need to worry about). As a PP said, unless she's saying, "Forget the stupid foundation and focus on my suggestions!" then I don't really think she's doing anything wrong in this one situation.
In terms of her ongoing talkativeness/neediness, my personal advice is to just tune it out. It doesn't sound like you see her that much so you just need something that will get you through those rare occasions. Smile, nod, beandip and if she doesn't take the beandip, find something that urgently needs your attention in another room.
Toot's advice is also very good.