Well, Kelly's original question dealt with the business aspects of big bust modeling. Granted that she could choose to start modeling right now with her natural E cups, however this would in effect make her just one more natural big boob model in a "sea" of other natural big boob models, many of whom are much more famous, many of whom do big time XXX, and many of whom escort. As such, she might get a magazine offer or two, but it's unlikely that she would make much money as a natural big boob model unless she did the same as the others in regard to XXX and escorting.
We all know that regardless of whatever kind words and opinions are expressed in support of girls with large but less than gigantic breast sizes, that without resorting to XXX or escorting the only serious earnings power i.e. magazine covers, mainstream club feature, super popular website, belongs to the handful of girls with breasts in the gigantic category. Kelly waiting to get big custom made implants and then making a first impression with J cups instead of E cups would catapult her into the "primo attention zone" right away in regard to magazine editors, feature booking agents etc.