@BLR, welcome to THS Forum. A two-week housesit is not an atypically long duration. Most of our housesits (~50) have been longer than two week duration (up to three months). It is our impression that shorter duration housesits appeal to housesitters that are local to your pet parent. Longer duration housesits may appeal to non-local housesitters.
Suggest that you add your THS listing to your THS Forum profile. Should you do this then Forum members may provide helpful comments.
We suspect that any lack of applicants may be due to factors other than housesit duration. Without reviewing the listing then it is guesswork. Similar Forum posts have identified poor listings (ensure great photos of key areas; complete info on pet(s) including exercise needs, other responsibilities, sleep location, duration left; info on local travel/transit; perhaps any local attractions). Suggest review listings of other Pet Parents in your area - they are your competition. Consider any aspects that may make your listing more appealing to housesitters. THS is a matchmaking platform - if your listing is appealing then it will likely attract housesitters.