Sarah Smith (33) made the 18-day trek up to the Mount Everest Base Camp, situated 5,380 metres above sea level.
She took on the trek to raise money for Cancer Research UK.
Sarah, who is currently Head of Year 5 at Dulwich College in Suzhou in China, said: “I climbed Mount Everest for all those that couldn’t; for all those fighting cancer and in loving memory of my Auntie Jill.”
Sarah’s aunt, Jill Andrews, lost her battle with breast cancer in July 2015.
Ben Petts, Cancer Research UK’s local fundraising manager for Lincolnshire, said: “We are absolutely delighted that Sarah has taken part in this challenge for Cancer Research UK.
“What Sarah has taken part in is not easy and I personally can’t thank her enough for the support.”
He said progress made in the fight against cancer was only possible with the help of supporters. Sarah has raised more than £1,000. To support her to help beat cancer visit www.justgiving.com/Sarah-Smith4u