I don't think she's going to mind not going. At one she won't recall it very well. My parents didn't even pay for activities when I was in high school and I was fine.
At that age they wouldn't know what they are missing, I think it's okay to skip right now
I think its totally reasonablle not to go on these extra events if your child is that young. My kids daycare does field trips (science center, apple picking) that are an extra fee and have some extra parents volunteer as chaperones. Under 18months don't go (some of them are still learning to walk, and are too young to really enjoy the activity, or still need extra naps) and it's optional for the older kids
What happens if she doesn't go?