If that happens, which as you said is unlikely, CC would still get the 3rd seed by virtue of their win over a higher seeded team (Harpeth).
I believe the best Waverly could do would be a coin flip for 4th seed if the Tigerettes beat CC and CW, and Sycamore losses to Harpeth. That would leave both Sycamore and Waverly with 8-6 district records with sweeps over Fairview and SC, being swept by Harpeth, and splits with the other teams in the district.
Now if Waverly only wins one game against CC or CW, they will finish with an identical 7-7 record as MC. IF Waverly beats only Creekwood AND CC beats beats Fairview (as expected) then Waverly is looking at the 6th seed. This is because MC will have beaten a higher seeded team in CC, which the Lady Cubs would become the 2nd seed. IF Wavo only beats CC, then MC and Waverly will have identical records against all the other district teams and a coin flip will be required to determine the 5th seed.
Bottom line, Waverly needs to win both of their games to assure themselves of the best seeding possible. The Tigerettes have been playing well lately. They will play two well prepared teams in CW and CC that have plenty to play for as well.