"Thank you for the best years of my life," Meredith said in an Instagram post.
Meredith graduated from JMU in Virginia and then earned her master's in pediatric nursing from Drexel University, her LinkedIn page shows. She works as a NIICU nurse at CHOP.
"Despite losing you, I am still the luckiest girl in the world to have been yours. I love you so so much. You were perfect.
"Some days it felt too good to be true. I love every single thing about you. You are my forever and I can’t wait to be with you again. I love you so much forever and ever."
The brothers were in town for their sister Katie's wedding to hockey player Devin Joyce Friday, Aug. 30. The wedding was canceled after Johnny, 31, and Matthew, 29, were struck and killed by suspected DUI driver Sean Higgins, 43, of Woodstown.
Matthew had been expecting a baby with his wife, Madeline.
Meredith shares two girls with Johnny, and posted a second tribute speaking to his dedication as a dad.
"The absolute best dad in the world. So caring and loving," she wrote. "The best partner to go through parenthood with. John never missed a single appointment.
"Was the best at putting the baby to sleep and the Apple of Noa’s eye. I love how much she looks like him. We are going to make you proud. We love you so so so much daddy."
Click here to follow Daily Voice Cherry Hill and receive free news updates.