The character of Abigail Spencer was portrayed by Imelda Corcoran.
She appeared in the season 5 episode "Jughead".
I wrote to her through her management agency, requesting an autograph,
but as yet have not had a reply. I'll update post if/when I receive a response.
I want to give a big thanks to Mark of http://lostified.com
He has acquired an amazing collection of LOST autographs and has been
very helpful in providing support and suggestions to me in expanding my collection.