Sheila has been teaching swimming for more than 20 years, coaching hundreds of people in the potentially lifesaving and hugely enjoyable art of staying afloat.
Katy Kowalska has seen her nine-year-old daughter, Eleanor, change from splash-happy toddler to fully fledged member of the swimming club in six years under Sheila's expert tutelage.
"I have never seen a woman who is so confident and clear with the children," says Katy, who nominated Sheila for our flowers, chocolates and champagne. "I have never heard her say anything negative towards them; whatever their level of ability she is supportive and full of praise."
Katy, who is herself a teacher, at Strathmore infants school in Hitchin, has nothing but admiration for Sheila, who routinely works a 55-hour week poolside in the noisy, chlorine-filled atmosphere.
"She is a natural teacher - supremely dedicated to her work," says Katy.
"She's not soft with them; she's very direct, and if they are not doing well, she pulls them up. All the children adore her.
"She has a dry, warm sense of humour and remembers everyone's name, which is itself worthy of an award given the number of children she teaches."
Sheila is in such demand that there's a two-year waiting list for her one-to-one sessions, just one of the many classes she teaches for all abilities and age ranges.
Operations manager Nicki Powell says the secret of Sheila's popularity is "her rapport with the kids; she knows how to get the best out of them".
Katy's assessment of her fellow professional is simply: "She is the best teacher I have ever met."
Is there an unsung hero in your school? Tell Sarah Bayliss, TESFriday editor, about him or her at the address opposite. Flowers kindly supplied by Marks Spencer