Sophia O Rourke came close in the opening two minutes of the game as the Rooks made a bright start against Southampton at the Dripping Pan.
A poor challenge on Megan Mackey in the area gifted the hosts a penalty but Umotong was denied from the spot in the 35th minute.
However, the visitors eventually broke the deadlock when Georgie Freeland fired home from a free-kick shot six minutes from half-time.
After the restart, Georgia Timms headed a corner onto Umotong s path, offering the latter a chance to make up for her earlier miss, and she made no mistake with her equalising header 17 minutes into the second half.