Make sure there are no typos in your name.
If not, then try to delete the whitelist.json file in your server (you can do this by selecting the file in your minehut panel file manager) and then restart the server. Once you've done this make sure to check that the whitelist is still on and try readding your name to it.
If all of the above doesn't work, you could try looking into disabling the default whitelist system (/whitelist off) and making your own with skript. Hope this helps.
To clarify, the events are not flash sales or limited time perks, they're game servers that the Community Event's Team creates. If you need an idea of what this looks like, I'd recommend looking at the other two previous posts.
A message should periodically pop up in lobby chat. It should say "click here" which is how you get the link, although minehut might not be doing that sponsor event anymore.
1.17 Currently uses Spigot instead of Paper. Paper has been proven to be a lot faster than spigot, however paper hasn't released a 1.17 version yet. They announced they were half way done with fixing their code sometime yesterday, so it's best to be patient until then.
You could try opening a support ticket although you'd most definitely need some proof that she actually owns the account (not just that you play on the server, but own it.) I find it hard to believe you'd forget your email AND account credentials.
It looks like minehut doesn’t allow you to transfer back to 1.16 yet if you’ve updated to 1.17. You can either wait until this gets resolved or you can reset your server. I’m 90% sure backups wont go around this issue. Sorry for the inconvenience.
In your server panel, click the edit server button if you havent already and head to the section that says “settings” and you should be able to change stuff there. You will have to restart your server for any changes to go into effect.