Last-Minute Embassy Trip

My daughter is 10 months and was born in the UK, so she doesn't have either passport yet. We did have her an appointment at the US embassy in March, but an appointment opened up for February 2, so we snapped that one up. I'm really nervous for some reason! We're in West Yorkshire, so quite a haul to get down there. We're having a friend drive us since train tickets were going to be £280  

We're going to get her picture taken at Gould's as recommended in some other threads. We'll be taking our documents in with us since we didn't have enough time to mail them in advance.
-my US passport,
-her long [British] birth certificate,
-marriage certificate,
-form DS-2029 (birth registration),
-form DS-11 (passport application),
-form SS-5 (social security number application),
-money,
-appointment print-out,
-passport pictures,
-my husband,
-husband's passport,
-prepaid envelope

Am I missing anything? Are there any other forms I need to bring already completed?

How about parking?  I read on a thread something about a congestion charge? Can someone shed some light on this? And are there any easy-to-find/use parking lots near the embassy? How much do they cost? (This is turning out to be an expensive endeavor, so the more I know about how much it will wind up costing, the better!)

And one last question: how long did it take for you to receive your child's SSN after you r appointment? When we got our son's while we were living in the US, it took about 3 weeks. Just wondering if it's a lot longer or about the same. Any other tips would be welcomed! I don't know why I'm so freaking nervous about this!

I read on a thread something about a congestion charge? Can someone shed some light on this?

http://www.tfl.gov.uk/roadusers/congestioncharging/

I'm sorry I don't know more of the answers, but as to the congestion charge, you can click on the "location check" link and enter the post code of the parking lot and it'll tell you if you have to pay the congestion charge.  You can also pay the charge in advance from that website, or pay it after the fact (it's slightly more) if you forget.

good luck,
Carl

Thank you for the link! This is such an odd concept for me, haha. Would it be okay if we parked, then paid online (via my husband's mobile)? I'm not sure where we'd be parking, so I wouldn't be able to put in accurate details till we got there.

How are they able to keep track of who doesn't pay? (Rhetorical question, as there may not be a clear answer!) And just in case, would this be something we could pay in person when we parked, like if there was a parking attendant? Or can it only be done online?

And sorry, one more question! How do you prove that you've paid? Do you need to print the receipt and have it in the car window? I get the feeling I might be overthinking this!

Yes, you're overthinking a bit. 

You don't need to put in where you're going to be parking.  You just need to pay if you know you will be in the zone during that day.

They have cameras posted around the entrance to the zone and they KNOW when you enter into the zone and haven't paid.  I had a friend who went in it for about 10 minutes and didn't realize it, but he still got a fine. 

You don't pay a particular person although you can pay at a shop or post office.  Read how to pay:
http://www.tfl.gov.uk/roadusers/congestioncharging/6744.aspx

Read the FAQ on that page that camoscato posted - it has all the answers to your questions.

Ooh, that's really neat that they're so on top of it with as much traffic as they must get! Thank you I think I'm letting my unbased anxiety over the whole trip get the better of me