Have you ever tried to reconnect with a friend or ex friend but they don’t reply back?

A month ago, I tried to reconnect with a really good friend of mine. I added her but she hasn’t accepted my friend request and it’s been a month. I messaged her but she hasn’t responded. Two two weeks later I sent another message but she hasn’t responded. Maybe she doesn’t go on Facebook much anymore or maybe she’s just trying to ignore me or be possible aggressive. I don’t give up that easily so I my try to find some people to try to get her to respond to me. I really miss her so much and she’s been the best friend I’ve ever had and some thing about her is very special and I’m not letting that go. Everyone deserves a second chance. We’ve been friends for about five years and then we didn’t speak to each other for a couple years. Should I keep trying to reconnect or just move on? I don’t wanna let that friendship go.