Hi there and
to the forums!
I'm glad she's doing fine in the travel cage for now, but she does need a bigger cage. Just because she's relaxed in it doesn't mean its a good long term home for her. Also, I think you may be misreading her climbing up and down the small cage as excited behavior when it may mean in this case that she's confused as to where all her space went. It is quite true that budgies, when excited or happy, are quite the acrobats and love climbing all over their cage, but they also do this when they feel cooped up and unhappy.
You should never put her in with the finches-- budgies are parrots and have the beaks to prove it. It's very possible that should one of the finches annoy her, she would unintentionally hurt him.
What you definitely need to do is go out and get her a new cage-- the minimum size for a single budgie is 18 in. x 18 in. by 18. in, but bigger is always better. She'll be much happier in it long term for sure, and will have plenty of room to stretch and climb as will as flap her wings.
Here's a link that might be helpful!
I look forward to meeting your little ones when you get a chance!
Meanwhile, you've come to the best place to learn even more about budgies! Be sure to read through the information above, which includes the forum's many Budgie Articles and "stickies" (threads "stuck" to the top of each subform for easy reference) to ensure you're up to date on all the best practices for budgie care.
If you have any questions after reading through everything, be sure to ask!