A Little Advice Please?

[MTSUGURL]

I've been invited to an event to get to know some alumnae of an NPC sorority in my state. I've exchanged a few emails, texts and had a long, very pleasant conversation with one of the women that will be there, (she is the one who introduced me to the woman that sent me the invite.)
Here's where I need advice:
I don't have their addresses, and I feel that in this day and age asking someone you don't know our don't know well for an address is creepy and somewhat inappropriate. I would like to take a small thank you gift or card for both women to show my appreciation for the invite. Good idea or would it come across as trying too hard? I really want to do more than send an email after the fact.