Shenandoah, the 2016 ODAC champion, ends its season with a 10-9 record.
W&L controlled the contest early, scoring its three goals in the first 20:26 of the game and holding SU to just two shots in the first half.
Shenandoah completely changed the complexion of the game following the halftime break, taking eight of the 12 shots in the half and earning seven of the nine penalty corners granted.
After coming close on numerous occasions, including Kayla Alderman hitting the pipe early in the stanza, Lingo broke through in the 65th minute by finishing the cross-goal feed from Leighty to cut the deficit to two.
SU would earn one more penalty corner following the Lingo goal, in the 68th minute, but was unable to get off any shots.
Isabella Morande had two of her eight saves in the final two minutes.
Washington and Lee ended up with a 13-10 advantage in shots with Shenandoah taking nine of the 14 corners awarded.
The Hornets will announce their 2018 schedule in early spring.