Nukkit VS Geyser

NukkitX by default doesn't have anything above 1.12 Mineacraft. It also doesn't have maps by default (though you can use a plugin for this). One other way to see is taking a look at the currently open GitHub issues.

I'm not the most well versed in Bedrock servers, but I think you could use something like Nukkit or PocketMine-MP for the mean time, as they should have 1.18.3 versions still up for download.

Is there any documentation on Minecraft bedrock server. How do Nukkit, PocketMine and potentially other server software figure out everything. Or is it just reverse engineering. If so, how can they update to new versions so quickly. All I could find was about addons and commands. (This) Or maybe someone's doing all the work on figuring out and sharing and all server developers just use it?

There's a mod for Java servers that allows Bedrock players to join as well. https://github.com/GeyserMC/Geyser

Geyser: Download Geyser

Geyser is a plugin that you can install on your server to enable crossplay. You can download it from their official website or from their GitHub page. There are different versions of Geyser for different types of servers, such as Spigot, Paper, BungeeCord, Waterfall and more. Make sure you download the version that matches your server type.

She plays bedrock edition on her iPad. MacOS only supports Java edition. You need something like Geyser to play together or use software like Parallels to install windows on your Mac so you can play bedrock.

geysermc is a plugin that allows bedrock players to connect to Java servers https://geysermc.org/

In case you're willing to give it a shot, see: https://geysermc.org/

Its a plugin called GeyserMC that lets Bedrock players join Java servers.

Geyser: Geyser is a proxy that lets Bedrock Edition players join Java Edition servers. It supports most Java features and cross-play between different platforms. You can use it as a plugin or standalone proxy. You can download Geyser from here and join their Discord for support here.