Are you really worried about not being ticklish?
Are you worried she doesn't have fun and this diminishes your chances to tie and tickle her, which is what you really want.
If she's not into tickling, perhaps it will be awkward at first. But as long as you continue, she will get more experienced and will maybe start enjoying it, and also being more “effective”. Give it a go, and let us know how it goes.
Hopefully she’s a good tickler because some inexperienced lers aren’t as good at finding tickle spots and reading reactions. If she has nails that can help. I would say maybe be blindfolded as well? That can help increase the tickling sensations.. If you’ve never been tickled you might be surprised at how sensitive you are if she’s good and tries out different spots.
A lot of girls who say they hate being tickled associate it with childhood torture where it happened without out their consent and they felt victimized and embarrassed by their own involuntary reactions.
What I've found is that some (although not all) of these same girls can be persuaded to change their mind about it, if you explain that they just haven't been tickled properly, i.e. in a way that's not overwhelming, that's based on their consent and that will also be fun. You tell them you want to re-wire how they experience being tickled. You might be surprised. But they have to like you first.