Jenna, can I ask you something?
Is she pink, bright-eyed and perfect and healthy? SHE'S GAINING WEIGHT. She is, I promise! Humans have been breast-feeding for hundreds of thousands of years. Your body, and her body, knows what to do.
If you are really worried about the amount she's taking in you can express, measure and give it in a bottle, it's sometimes reassuring. Also, check if her fontanelle is depressed, it's a way of checking for dehydration. DON"T freak if it's just a little bit sunken - that's normal!
She's not going to get stolen, I promise you. There's a reason every child-napping case in the UK ever has made it into the newspapers - it's incredibly rare. Like rarer than getting struck by lightning and getting a snog off Brad Pitt. It's just NOT going to happen (unless you're Angelina Jolie in disguise
)
You won't stop worrying and you'll probably ignore this post because the first few weeks are so frightening and bewildering, but I can promise you a couple of things, firstly that you are doing absolutely fine, and secondly, it will start getting less scary soon. I PROMISE you it will.
And.... breathe, keep breathing, and enjoy your little one.