Gilbert, why don't you email her and ask to talk about it with her? If you are seriously considering paying for a session with her, she'll be glad to converse a few times via email.
I looked at her section at PA. Don't make the assumption that she's "into" tickling just because she lists tickling as something she'll do in a session. Remember, as bdsm activities go in a pro dungeon, tickling is practically money for nothing. Most subs in bdsm houses LOVE to do tickle sessions because they don't have to worry as much about being hurt by the client. They can giggle and squirm for a half hour and collect as much as if they were whipped for a half hour.
She might be VERY ticklish, or she might be mildly ticklish, or not ticklish at all -- and the only way you're gonna find out for real is if you pay to find out for real. SO -- are you into anything else bdsm-wise? If you got there and put her in restriants and started tickling and discovered she wasn't really ticklish, could you move on to something else and be satisfied? If not, be absolutely up-front with her when you contact her (and for God's sake, be somewhere close to the point ... she works for a living. Don't make her read a book.) Just tell her that you would like a tickle session, but you would be disappointed if she wasn't extremely ticklish (or ultra ticklish, or mildly ticklish, or whatever level would satisfy you). I guarantee she'll be straight with you when she answers. The last thing she wants is a disappointed customer, because disappointed customers don't tip -- and she makes the bulk of her pay from tips. So, she has no reason to mislead you. Instead, she'd rather book someone she's sure she can satisfy.
That said, she might tell you she's ultra-ticklish and she expects you to know when to let her rest, etc... If she brings up rest periods and the like, that's a good sign that she's very ticklish. If she never mentions anything except a safeword, that might be a bad sign. If she can take a half hour of nonstop tickling, she's either a MAJOR ticklephile or she's not really ticklish.
Just a thought or two. Hope it helps.
-Pete