
If this doesn't fix it then I'm sorry I couldn't be more helpful.

I dunno if you ended up figuring out the solution way back when, I hope that you did but if not then I hope this response helps and you finally get the chance to play with your sister again.

To join Enigmatica2 server you will need twitch/curse launcher found here. On my Windows laptop I went into Settings and clicked home, then clicked Network and Internet, then clicked the Wi-Fi tab, then clicked manage existing networks, then clicked the Properties button under the internet connection I was using, then switched from Public to Private. Free Minecraft Server Hosting 24/7 With Free Plugins Mod Included - NO Credit. If it's not your connection then it might be hers but yeah. If it's not the firewall it might be that you have your network settings for the internet connection you use as "public" instead of "private." Private networks allows your computer to be discoverable and would therefore let your sister actually be able to connect to your server since it's being ran on your computer. Kinda like SkyBlock, except you dont start with a. I guess this is about a year late, not sure if you'd check the board for an answer more than a year and a half later but I just figured this out with my friends. It packs a bunch of the best Minecraft mods of all time into a single.
