"Take things slowly" means whatever it means to you and your partner. It sounds like she has the clearer head here and will level-set, but if you are unsure, ask her what slow means to her.

Honestly, I can take about 15 minutes of an adult partner acting like "a teenager" or "a hopeless puppy in love" - especially after only 2 dates in 3 days. It's so obvious that is all about hormones, and not about getting to know each other for real, and that is exhausting in a partner. I would advise you to turn that NRE to other things - use the energy in other parts of your life (get up early and go to the gym, sign up to volunteer with a charity project, take your other partner out for a fun date, do some daydreaming) and don't overwhelm an experienced solo-poly partner.