A long time platonic friend is going to a wedding in a few weeks and has invited me as her plus one. She is buying the wedding gift and saying it is from both of us. I'll be transporting her to and from the wedding, which is in her city (where I used to live too). I'll be coming in from my city, an hour away, and returning there afterwards.
What is traditionally expected of a "plus one" for a wedding? I don't think she is expecting anything, but perhaps she just assumes that I will do certain things, like bring flowers or a corsage. I've never been a plus one before and my knowledge of the social niceties is very limited. We are not dating and have never dated in the past.
I am in Ontario, Canada, as is my platonic friend and the wedding.
I realize that social rules are not necessarily as hard and fast as, say, rules of the road or tax legislation but I feel as if the general principles for plus ones must be known. I just don't know them. Some guidance here would be appreciated.