It is not the lack of toes that would prevent me from tickling, I could care less. It would be that the woman did not desire it. In most interpersonal interactions, non consensual behavior is not the wise course to take. I would honor the woman's request to be left alone.
I would have to agree with both Myriads and SoleSeeker, if the lady didn't want you to I would certainly would respect her wishes. 🙂 But if she asked you to tickle her I would honor that wish!