for beginners, too loose is usually better than too tight. afterwards, you can discuss if it needs to be tighter next time - starting out too extreme could be scary for her - you never know until your actually tied up how you're going to react and feel.
You can’t truly call yourself peaceful unless you are capable of violence. If you’re not capable of violence, you’re not peaceful. You’re harmless.
Echo Her Spriteness - start loose so that she can slip out if it becomes too much. Some people have a violent reaction to being restrained in this fashion even if beforehand they express a desire for it.
As with all things, start slow and work your way up, and always listen, observe and obey set limits.
Maybe a bit too late, but I saw this and found the reactions a bit to easy. I'd say to tie her tight and keep scissors with you. You may be nice trying to be careful with tying her a bit too loose, but if she wants to be tight down, she doesn't want you to be careful. You may be letting her down by not tying her up right. Ofcourse, always keep it save and have scissors near, be sure they cut through the rope easily and she should be alright if you tie her too tight.
If i'm too late, I hope you had a wonderfull time.
Simple solution would be to ask what she wants. If she says loose great, if she says tight & freaks you do have a safeword