Honestly, I haven't spent much time looking at her autograph but compared to several others I've seen it looks close, probably good. I especially like the Margot portion. I've seen better examples of her last name though. Not sure what the price is on this one but, with a quick look, it appears that a decent signed photo with a PSA or JSA authentication can be had between $50 - $75. Looks like she's done plenty of signings.
I understand your situation. I live in the hills of central Tennessee and wouldn't have time for conventions anyway. I enjoy my hunt online. Take time to learn this and you will be richly rewarded.