Talk to her about it.
Your interpretation of her behavior is that it is because she thinks of you as inexperienced. Many of the other answers have given suggestions for alternate interpretations to her behavior, and some give suggestions as to how to shut the behavior down, which, without knowing why she does it could just needlessly put additional stress on the relationship.
The only way to know why she is doing it is to talk to her about it. Ideally you could just ask her directly, let her know why you are asking, and assure her that if you don't understand something you will ask.
You know her better than any of us so should have a better idea how she would react but consider starting with something like this:
Hey Sue, I know we've not been working together very long and are still learning what to expect from each other. I've noticed that when we talk shop you often fall into pretty basic explanations of what I consider standard topics.
Why is that?
I'm hoping it is because X or Y (give one or two of the more generous interpretations from the others), but it often feels like I've given you the impression that I need these things explained. If that's the case, it seems we are wasting valuable time that could be used more productively discussing the required features. If you are unsure of my experience with a topic, you can ask what I know about it, and if the discussion touches on something outside my experience trust that I'll ask.
I wouldn't initially interrupt her while she is in one of her explanations to have this discussion because it seems more likely to come across as reactionary or defensive. Better to approach her separately.
Going forward from there, depending what comes of the initial discussion, when and if it happens again, you could interject that this is one of those basic explanations, or start applying some of the suggestions from the others on how respond in-line.
As an aside:
In a project last year I had to explain what JSON was to couple of team members. They both have at least a decade (or two) of industry experience on me, and at various points in their careers both had worked on web projects. They just never worked with any frameworks or needed techniques where it was particularly relevant.
In the same project, we had some of the business folks we were working with interchangeably use the same two or three terms referring to two closely related but (as it turns out) distinct topics. Which topic a given term meant depended on which of them used it and in what context. It actually took a few iterations for us to catch on. Up until that point, it was never clearly laid out that there even were distinct topics. They assumed we knew, and we assumed they were all referring to the same thing.
More recently in a discussion of a mis-configured application, I had a team member go off on a tangent for a half-hour proposing misguided changes to our configuration framework to prevent the wrong default environment from being selected, when the problem was that the application had the wrong default value for an individual setting. (The framework allows for default fallback values in case it is not overridden for the current environment, the application had what should be a production only value set as default, so when a test environment didn't override it...)
What's the point?
Almost any professional field is broad enough that for any given person, regardless of level of experience, it is impossible to know everything. Everyone will have different holes in their knowledge and experience, and there may well be subcultures and specializations with clashing lingo. You can't just make assumptions about what other people know, or mean, or why they make certain decisions.
It has been my experience, unstated assumptions can (and eventually will) be very expensive. A few minutes spent to ensure everyone is on the same page before beginning any discussion will save a great deal in the long run.
In this case your assumption that she is doing this because you are self taught, and/or (if your assumption is correct) her assumption that you need the instruction is causing harm to your working relationship.