Good thing you got the kiss.
Don't mess it up by talking about other girls, it would make you seem as a player and she'll back off.
I've went through this a dozen times to be honest. Now that you have your kiss, try escalating to sex.

The more sex, the more the attachment.
By the way, try not to show that you like her more than she likes you. Investing too much in her too early in the process will get you rejected and "I don't want to do this anymore" responses. Trust me, it happened to me.

Keep it casual, keep gaming other girls and having sex with this girl until you are official. Don't worry, she'll bring up the topic after a reasonable amount of sexual interaction.

Good Luck

If you like her, tell her.