(Richard Family)

Four months ago, on April 15, the Richard family of Dorchester, Mass., stood on Boylston Street watching the Boston Marathon before two bombs exploded near the finish line.

Martin Richard, 8, was one of three people killed in the terrorist attack. Martin's mother, Denise, was gravely injured in the attack and his sister, Jane, 7, lost a leg.

After months spent in hospitals and hundreds of hours of physical therapy for Jane, who has learned to walk with a prosthetic, the Richard family is adjusting to life back home.

WATCH: Remembering 8-Year-Old Martin Richard

In an update posted to their blog, the family said moving forward without Martin hasn't been easy, but they've been struck by Jane's remarkable progress as she becomes comfortable wearing her prosthetic leg.

"When she is able to have it on, she struts around on it with great pride and a total sense of accomplishment. Her strength, balance and comfort with the leg improve every day," the update said. "Watching her dance with her new leg, which has her weight primarily on the other leg, is absolutely priceless."

The Richard family said Jane "continues to be an incredible source of inspiration" and is looking forward to going back to school in a few weeks.

"Throughout all that has happened, we have worked hard to maintain our bond as a family," they said. "With the love and support of family and friends, including those who were total strangers just four months ago, we feel like we are succeeding."