Hate to be mr. downer here but you do realize that this is absolutely prohibited by RunDisney (and most races in fact) and could get you banned from running any future events if caught and the person who buys it would also be removed from the race what you actually could have legally done is deferred her entry into a future event
Quoting from RunDisney: Race entries/bibs are not transferrable from one person/participant to another person/participant. Sale, trade and/or transfer of race entry/bib number is strictly prohibited and may result in the disqualification of and/or banning offenders from participating at future events. Anyone caught attempting to sell or transfer their race entry/bib to another person/participant, pick up another person's/participant's race entry/bib, or participate in a race using another participant's race entry/bib, will have said race entry/bib cancelled and/or revoked, be disqualified, and be removed from the race without refund.