From what I've read, its quite common to still have one or 2 baby teeth. It's more common for people to be missing teeth than having extra teeth.
But once there are a few more missing it can be an issue. I've read that the whole shape of the jaw can change & you can eventually loose the room to have adult sized teeth in that place.

Her 2 top first molars haven't come in. Her eye teeth have now decided to spread out & sit where her molars pretty much should be. I actually had a look & now see why her teeth are so gappy. They're just making the most of all the room!

So I'm thinking braces might be the first step. Bring the teeth back to where they should be?

Again, just me guessing.

Debt, come at me! Lol