If you and I, plus all our family members, and our dearest friends plus all their family members were to learn 500 new things every single day for the rest of our lives, when the last of us was gone, and they tallied up all we’d learned, together we still would not have known it all and would not have known how to do it all.
So it stands to reason that your VA won’t know it all or how to do it all. Your VA won’t even know how to do everything you—all by yourself—want her to know how to do (or at least the probability of that is incredibly small).
And even if you happened to find the one VA on the planet who can do everything you need today, at some point, probably not too far in the future, you’re likely to read something, see something, or hear something mentioned and, when you ask her about it, she’ll never have heard about it. Boom—there goes perfection.
So don’t look for perfection—it’s a pipe dream.
Instead, look reality in the face and know that it’s inevitable that your VA will need to learn things to be able to support you well. Some of those will be things she’ll immediately see can help her in her work with other clients. And some of what she’ll know will be very unlikely ever used with another client in the history of, well, ever.
When you ask a VA to learn something so that she can do something specific for you, she’ll evaluate whether or not she’s likely to be able to use that new skill with other clients. If she tells you it’s something she might use for another client, it’s fair for her to charge you for half of her learning time and associated fees to learn it. And if she tells you she’s unlikely ever to use it with another client, it’s fair to expect you to pay for 100% of her learning time and associated fees to learn it.
You can choose to pay her, or find someone else to pay who already knows how to do what you need. What’s not fair is to expect her to carry 100% of the expense of learning on her own.