Hi Heather, first

don't ever feel the need to apologize for writing at length on the forums - the whole point of this site is communication and brainstorming and we can't do that effectively without putting our thoughts to words.
That said - I don't necessarily think that people are going to see you as 'pushy' (unless you really actually are) you have the benefit of already being a part of this community and network and you are simply translating your unique (and valuable) insight as well as your skill set to a new way of adding to that community.
I don't think it's a negative that you're seeing a business opportunity here and as long as you go into it with the actual ability to back up your service offerings with awesome results, then more power to you!
SO many VAs have transitioned to working for themselves withing an existing market they're already a part of in some way.
So do go into that convention prepared to walk the talk and know what you have on offer - because the chances are that you will leave there with a new client or at least some interest if you do! Confidence is key. You know what you have to offer to this market - can you communicate it clearly?
Aside from that, I think being vocal about what you're doing when you're at these other events you're looking to participate in is a good start.
You might also consider reaching out to local authors and writers (or just other entrepreneurs to start making connections) through a networking group like Meetup or similar.
Clients will come to you through the most unusual places as soon as you decide you're really doing this and start marinating in the mindset that your business will be successful and that you're super good at what you do (again, confidence!).
I once had someone try to hire me in line at a grocery store after a casual conversation turned to what I do. The same has happened in yoga classes, at parties, and more. Not all of those people turned out to be a good fit and not all of them contracted me - but you get my point
Also, just asking other people to refer you is a superb way to grow your potential client base. If you have colleagues, know authors who aren't looking for a VA but might know someone who could use you etc etc
Don't give up and don't be shy! You'll get there....
(how's that for long?)
