You can guess however where the user will read your message on. Business related it's most probably an email client on a desktop. Sending personal messages most likely on phone. So format accordingly.
In this sitation its better to format: "Hey! It was great meeting you! Pretty sure my ears will be ringing for the next week haha"
And then wait for the girls reply. Regardless on the device she reads, it will look good and doesn't come off as needy. Then your next message will be to ask her out on Saturday. And if she doesn't reply, she's not into you and leave it there ;)
Or we should invent responsive texts, depending on the device it adds or removes words...