can i be in training?

A couple of weeks ago, I received a card in the mail. It contained information about the Leukemia Society's Team In Training. There is a marathon in Houston in January. The marathon is a full and half marathon. Half is 13.1 miles. Walking. I decided to go online and do some research. My sister lost her battle with Leukemia almost five years ago. She was only thirty-nine. I decided it would hurt me a bit to attend the TNT meeting and find out if this is something I could qualify for.....and actually finish. The meeting is this coming Saturday in Houston. I hope I get the answer I want! I would love to be part of a good cause and do what I can for the society and the personal accomplishment of finishing a marathon!