It's not like there are schools for MPAs or a professional association enforcing standards. Everyone—clients and operators—learns on the job from each other and from experience good and bad. Yours might be her first such request. So you need to understand what you're after and try to express it so you achieve it.
There are lots of obstacles to that, like what's legal, what's customary (in the GTA in general and in the particular MP), what she prefers and what she hates, but as a paying customer, it will be most unusual for your request to provoke anger, insult or painful embarrassment from her. Just be pleasant and polite, and assume she's heard it before.
FWIW: My sense is that there's an increasing standardization—fueled perhaps by people taking advice from BBs—of token massage w/ teasing, then convo about extras, delivery of same w/ a flip and final moment of joy, so some junior MPAs may be taken aback at 'extras' up front, especially if they're FOB. And if you and she and the spa are all making each other's acquaintance for the first time, she may want some hands-on assurance you're a fun guy and not a cop. But there's no harm in asking, or in telling her it isn't really the massage you care about.
But be confident: This is only a point of confusion among customers, she knows what she's selling and how, and I'll just bet, if jason12 can even remember the occasion, that he and she sorted it out OK. Nothing wrong with a tad of embarrassed giggling as an intimacy aid.