Hello ladies,
I've lurked quite a bit over the last year and have learned so much, so thanks for that!

I received a destination wedding invitation last week from a woman I was friends with through elementary to high school, but we haven't actually spoken in at least the last five years beyond the occiasional facebook comment. Her wedding is next January and with the invitation there was just the print out with instructions for placing the deposit (by April with full payment in October). But there wasn't an RSVP card for me to send back to her to indicate that my FI and I would not be attending. If no card was provided, do I just ignore it or is it my responsibility to contact her. Would a message via Facebook suffice, or does it need to be written correspondence? Any advice would be greatly appreciated.
TIA!