Sr. Virginia never mentioned cannibalism. She was a straightforward facts-and-names sort of history teacher, either uninterested in the backstory and motivations of historical figures or someone who though 11th graders didn't need to know such matters. As I remember it, she taught us that Jamestown survived through hard work, faith, and tobacco, glossing over how close the colony came to failing.
I never went to Jamestown when I lived in Richmond. Growing up in Philadelphia, I have a bit of a bias towards the Delaware Valley as the most important player in colonial history. Sure, Jamestown was first, but it's also on a God-foresaken swamp and why would a stressed law student with no cash flow want to go there? Come to think of it, why did a group of fortune hunters on a mission from God go there? The land was poor, the people unprepared, and the management incompetent, so it was only through creative (or deceptive) marketing that the colony managed to get a second wave of immigrants. Seven ships set out in May, 1609, and six found their way to Jamestown where the disease-weakened survivors became burdens to the starving and under-seige colony. They just weren't prepared - no skills, not enough supplies, and they antagonized the Native Americans with which they attempted to trade for food. A majority of the colonists died from disease and starvation, even after they resorted to eating the recently dead. They needed a miracle, and it came in the form of a shipwreck.
The Sea Venture had separated from the rest of the fleet during a hurricane and ran aground on Bermuda. While both Europeans and native Caribbeans had been to Bermuda, no one had settled there because of the shallow waters inlets and treacherous currents. Prior visitors had left pigs, though, which now ran wild, providing (along with abundant fish and fruit) needed food to the weakened castaways. After a few months of recuperation, the Sea Venture passengers and crew repaired their ship and built a second one, finished the voyage to Virginia, and saved the colony. Healthy bodies (and the expedition members best suited to leadership) stabilized the colony. It wasn't a success yet, but the stories brought back to England encouraged younger sons to consider Virginia as a place to make their name (and provided a "ripped from the headlines" plot for Shakespeare's last play, The Tempest).