Poppi cofounder Allison Ellsworth said she's teaching her children how to value and grow their money. Vivien Killilea/Getty Images for Poppi Poppi's cofounder Allison Ellsworth said she's teaching her children how to invest. She put $5,000 into her three children's Fidelity accounts and let them pick stocks and experience losses. Ellsworth and her husband exited Poppi last year after PepsiCo acquired it for $1.95 billion. Poppi's CEO and cofounder, Allison Ellsworth , said that she's opened $5,000 investment accounts for her three kids under 10. In an interview with The Wall Street Journal released on Sunday, Ellsworth spoke about how she's teaching her three children about investing after their latest windfall. Ellsworth and her husband, Stephen Ellsworth, sold their prebiotic soda brand , Poppi, to PepsiCo last year for $1.95 billion. She said her children, who are four, seven, and nine years old, are very curious about investing. "So we opened them three Fidelity investment accounts," she said.…