She lost her job after her maternity leave. Now she leads an accounting institute

As the fourth female president of the Institute of Chartered Accountants in England and Wales (ICAEW), Julia Penny knows what it takes to succeed in business.

Despite her passion for her work, Penny's path to her job wasn't easy.

"On the first day back of maternity leave with my first child, I got made redundant," Julia Penny told CNBC's My Biggest Lessons.

Her first reaction was despair, but she began reaching out to her network for ideas.

"I talked with others, I talked with an old boss and they said: 'You could do (accounting) freelance. You could teach students of accountancy,'" she explained. Penny said she then picked herself up and carried on.

Having a group of people to on lean on for support is an example of why Penny believes networking is important to one's career.

"Ultimately, business is about people, not about numbers," Penny said. "We live in a diverse world. We might all try to be perfect. But of course, that's not going to happen. So we need to learn from our failures as well as our successes, and we need to help others too."

Those are just some of Julia Penny's five biggest lessons. Watch the video above for more.